Pde5 inhibitor powder formulations and methods relating thereto

ABSTRACT

Novel dry powder compositions comprising and methods relating thereto are provided. The dry powder compositions comprise PDE5 inhibitors, such as vardenafil, or pharmaceutically acceptable salts or esters thereof. The dry powder compositions may optionally include an carrier/excipient. The concentration of active agent may be at least about 2% by weight. Methods of aerosolizing the dry powder compositions and using them to treat various diseases are also disclosed.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. application Ser. No.15/102,957, filed Jun. 9, 2016, which is a 371 national stageapplication of International Application No. PCT/US2014/069392, filedDec. 9, 2014, which claims the benefit of U.S. Provisional ApplicationNo. 61/913,734, filed Dec. 9, 2013, and U.S. Provisional Application No.61/913,744, filed Dec. 9, 2013, which applications are herebyincorporated by reference in their entireties.

FIELD

The invention relates to powder formulations of PDE5 inhibitors andmethods relating thereto.

BACKGROUND

Phosphodiesterase type 5 inhibitors (PDE5 inhibitors) block thedegradative action of cGMP-specific phosphodiesterase type 5 (PDE5) oncyclic GMP in the smooth muscle cells lining the blood vessels supplyingthe corpus cavernosum of the penis. These drugs, including vardenafil(Levitra™), sildenafil (Viagra™), and tadalafil (Cialis™), areadministered orally for the treatment of erectile dysfunction and werethe first effective oral treatment available for the condition.

PDE5 inhibitors have also been studied for other clinical use as well,including cardiovascular and heart diseases. For example, because PDE5is also present in the arterial wall smooth muscle within the lungs,PDE5 inhibitors have also been explored for lung diseases such aspulmonary hypertension and cystic fibrosis. Pulmonary arterialhypertension, a disease characterized by sustained elevations ofpulmonary artery pressure, which leads to an increased incidence offailure of the right ventricle of the heart, which in turn can result inthe blood vessels in the lungs become overloaded with fluid. Two oralPDE5 inhibitors, sildenafil (Revatio™) and tadalafil (Adcirca™), areapproved for the treatment of pulmonary arterial hypertension. PDE5inhibitors have been found to have activity as both a corrector andpotentiator of CFTR protein abnormalities in animal models of cysticfibrosis disease. (Lubamba et al., Am. J. Respir. Crit. Care Med. (2008)177:506-515, Lubamba et al., J. Cystic Fibrosis (2012) 11:266-273).Sildenafil has also been studied as a potential anti-inflammatorytreatment for cystic fibrosis. Oral PDE5 inhibitors have also beenreported to have anti-remodeling properties and to improve cardiacinotropism, independent of afterload changes, with a good safetyprofile. (Giannetta et al., BMC Medicine (2014) 12:185). However, oraladministration of PDE5 inhibitors results in poor and variablebioavailability and also extensive metabolism in the liver. (Sandqvistet al., Eur. J. Clin. Pharmacol. (2013) 69:197-207; Mehrotra, Intl. J.Impotence Res. (2007) 19:253-264.) If oral doses are increased beyondcertain levels, the incidence of systemic side effects increase whichprevents the acceptable use of these drugs. (Levitra EMEA ScientificDiscussion Document, 2005)

In view of the limitations presented by oral administration formulationsof PDE5 inhibitors, there is a continuing need for further improvementin pharmaceutical preparations that deliver increased drug doses to thelung.

BRIEF SUMMARY

In one aspect, provided is a powder pharmaceutical compositioncomprising a) at least about 2% by weight of a PDE5 inhibitor or apharmaceutically acceptable salt or ester thereof relative to the totalweight of the overall pharmaceutical composition, and b) at least onepharmaceutically acceptable carrier.

In another aspect, provided is a method of aerosolizing a powderpharmaceutical composition comprising a) at least 2% by weight of a PDE5inhibitor, or a pharmaceutically acceptable salt or ester thereof,relative to the total weight of the overall pharmaceutical composition,and b) at least one pharmaceutically acceptable carrier, the methodcomprising: providing an inhaler comprising a dispersion chamber havingan inlet and an outlet, the dispersion chamber containing an actuatorthat is movable reciprocatable along a longitudinal axis of thedispersion chamber; and inducing air flow through the outlet channel tocause air and the powder pharmaceutical composition to enter into thedispersion chamber from the inlet, and to cause the actuator tooscillate within the dispersion chamber to assist in dispersing thepowder pharmaceutical composition from the outlet for delivery to asubject through the outlet.

In another aspect, provided is a method of treating a disease in asubject in need thereof, the method comprising administering to thesubject via a pulmonary route an effective amount of a powderpharmaceutical composition comprising a) at least about 2% of a PDE5inhibitor, or a pharmaceutically acceptable salt or ester thereof, byweight relative to the total weight of the overall pharmaceuticalcomposition dose, and b) at least one pharmaceutically acceptablecarrier.

It will be appreciated from a review of the remainder of thisapplication that further methods and compositions are also part of theinvention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a ¹H NMR spectrometry spectrum for VarHCl.3H₂O (top)and Var(HCl)₂.xH₂O (bottom) according to certain aspects.

FIG. 2 illustrates a ¹³C NMR spectrometry spectrum for Var(HCl)₂.xH₂O(top) and VarHCl.3H₂O (bottom) according to certain aspects.

FIG. 3 illustrates the results of pH titration analysis for Var(HCl)₂,VarHCl, and VarBase according to some aspects.

FIGS. 4A-4F illustrates the results of instrinsic stability testing ofVarHCl.3H₂O as assessed by a HPLC high performance liquid chromatography(HPLC) according to certain aspects. FIG. 4A shows a HPLC trace forVarHCl.3H₂O as obtained from the manufacturer.

FIG. 4B and FIG. 4C show HPLC traces for VarHCl.3H₂O following aciddegradation in 1N HCl at r.t. for 48 hr and in 1N HCl at 60° C. for 4hr, respectively. FIG. 4D and FIG. 4E show HPLC traces for VarHCl.3H₂Ofollowing basic degradation in 1N NaOH at r.t. for 48 hr and in 1N NaOHat 60° C. for 4 hr, respectively. FIG. 4F shows an HPLC trace forVarHCl.3H₂O following oxidative degradation in 6% H₂O₂ at r.t. for 48hr.

FIGS. 5A-5D illustrate the results of VarHCl.3H₂O-lactose (1:1)formulation blend stability at different temperatures and humidities asassessed by HPLC according to some aspects. FIG. 5A shows a HPLC traceof the formulation stored pouched at 25° C. and 60% relative humidity(RH). FIG. 5B shows a HPLC trace of the formulation stored pouched at40° C. and 75% RH. FIG. 5C shows a HPLC trace of the formulation storedopen to ambient environment at 40° C. and 75% RH. FIG. 5D shows a HPLCtrace of the formulation prior to storage (control).

FIGS. 6A-6C illustrates the particle size distribution of micronizedVar(HCl)₂.xH₂O, VarBase, and VarHCl.xH₂O, respectively, according tocertain aspects.

FIGS. 7A-7C provide scanning electron microscopy (SEM) images ofmicronized Var(HCl)₂.xH₂O, VarBase, and VarHCl.xH₂O, respectively,according to certain aspects.

FIGS. 8A-8C illustrate the results of differential scanning calorimetry(DSC) analysis to assess the thermal properties of micronized vardenafilcompounds according to certain aspects. FIG. 8A shows the DSC thermogramfor Var(HCl)₂.xH₂O. FIG. 8B shows the DSC thermogram for VarBase. FIG.8C shows the DSC thermogram for VarHCl.xH₂O.

FIGS. 9A-9D illustrate dynamic vapor sorption (DVS) analysis ofmicronized vardenafil compounds to assess moisture sorption anddesorption behavior according to certain aspects. FIGS. 9A and 9B showthe DVS isotherm plot for micronized Var(HCl)₂.xH₂O and micronizedVarBase, respectively. DVS isotherm plots for micronized VarHCl.xH₂O areshown in FIG. 9C and FIG. 9D, with the Y axis reflecting either percentchange in mass or the stoichiometric water sorption and desorptionprofiles (ratio of H₂O vapor absorbed to dry VarHCl (mol/mol)).

FIG. 10 illustrates thermogravimetric analysis (TGA) of micronizedVar(HCl)₂.xH₂O to assess mass loss according to certain aspects.

FIGS. 11A-11C illustrate results of x-ray powder diffraction (XRPD)analysis assessing crystalline forms of vardenafil formulations aftermicronization. FIGS. 11A, 11B, and 11C show the diffractograms formicronized Var(HCl)₂.xH₂O, micronized VarBase, and micronizedVarHCl.xH₂O, respectively.

FIG. 12 and illustrates an exemplary conditions for preparation of a 5%Var(HCl)₂.xH₂O and lactose blend formulation. Components were handblended and then mixed in a shaker-mixer at 22 rpm-, 49 rpm, and 99 rpmfor 5 min, 10 min, 15 min, and 20 min. Extend of blend uniformity wasassessed by the coefficient of variation (% CV) sampling.

FIG. 13 is a block diagram of a method of aerosolizing a powderpharmaceutical composition according to some aspects.

FIG. 14A shows a cross-section of an exemplary tubular body having aninlet and a dispersion chamber according to some aspects. FIG. 14B showsa bead position with a chamber of the tubular body of FIG. 14A accordingto some aspects.

FIGS. 15A-15B illustrates the aerosol performance of a range of highdose Var(HCl)₂.xH₂O-lactose blend formulations according to someaspects. FIG. 15A shows a strong correlation of emitted dose (ED(%) andAPI concentration (% w/w) of 20%, 40%, 60%, and 80% API blendformulations. The amount of powder deposition in the inhaler device wasalso assessed and well-correlated with API concentration as shown inFIG. 15B.

FIG. 16 is a block diagram of a method of treating a disease in a mammalin need thereof with a powder pharmaceutical composition according tosome aspects.

DETAILED DESCRIPTION I. Definitions

The singular forms “a,” “an,” and, “the” include plural referencesunless the context clearly dictates otherwise. Thus, for example,reference to a compound refers to one or more compounds or at least onecompound. As such, the terms “a” (or “an”), “one or more,” and “at leastone” can be used interchangeably herein.

The phrase “about” as used herein is used to provide flexibility to anumerical range endpoint by providing that a given value may be “alittle above” or “a little below” the endpoint accounting for variationsone might see in measurements taken among different instruments,samples, and sample preparations.

As used herein, the terms “formulation” and “composition” are usedinterchangeably and refer to a mixture of at least one compound,element, or molecule. In some aspects the terms “formulation” and“composition” may be used to refer to a mixture of one or more activeagents with one or more carrier or other excipients.

The terms “therapeutic agent,” “active agent,” “active pharmaceuticalingredient,” “API,” “pharmaceutically active agent,” and“pharmaceutical,” and “drug” are used interchangeably herein to refer toa substance having a pharmaceutical, pharmacological, psychosomatic, ortherapeutic effect. Further, when these terms are used, or when aparticular active agent is specifically identified by name or category,it is understood that such recitation is intended to include the activeagent per se, as well as pharmaceutically acceptable, pharmacologicallyactive derivatives thereof, or compounds significantly related thereto,including without limitation, salts, pharmaceutically acceptable salts,N-oxides, prodrugs, active metabolites, isomers, fragments, solvates(such as hydrates), polymorphs, pseudopolymorphs, and esters. Suitableagents for use in the formulations described herein include, withoutlimitation, compounds which have the formula (I):

The compound of Formula I is chemically identified as2-[2-ethoxy-5-(4-ethylpiperazin-1-yl)sulfonylphenyl]-5-methyl-7-propyl-1H-imidazo[5,1-i][1,2,4]triazin-4-one,also known as vardenafil. In particular, the compounds include thechemical forms as set forth in Formulas (II), (III), and (IV) below,including vardenafil base (VarBase), salts (mono and bis), such ashydrogen chloride salts, and hydrates (mono, di-, tri-hyrdates), as wellas different polymorphs.

As used herein, the term “treating” refers to providing an appropriatedose of a therapeutic agent to a subject suffering from an ailment.

As used herein, the term “condition” refers to a disease state for whichthe compounds, compositions and methods of the present disclosure arebeing used to treat.

As used herein, “subject” refers to a mammal that may benefit from theadministration of a drug composition or method of this invention.Examples of subjects include humans, and may also include other animalssuch as horses, pigs, cattle, dogs, cats, rabbits, rats, mice andaquatic mammals. In one specific aspect, a subject is a human.

As used herein, an “effective amount” or a “therapeutically effectiveamount” of a drug refers to a non-toxic, but sufficient amount of thedrug, to achieve therapeutic results in treating a condition for whichthe drug is known to be effective. It is understood that variousbiological factors may affect the ability of a substance to perform itsintended task. Therefore, an “effective amount” or a “therapeuticallyeffective amount” may be dependent in some instances on such biologicalfactors. Further, while the achievement of therapeutic effects may bemeasured by a physician or other qualified medical personnel usingevaluations known in the art, it is recognized that individual variationand response to treatments may make the achievement of therapeuticeffects a somewhat subjective decision. The determination of aneffective amount is well within the ordinary skill in the art ofpharmaceutical sciences and medicine. See, for example, Meiner andTonascia, “Clinical Trials: Design, Conduct, and Analysis,” Monographsin Epidemiology and Biostatistics, Vol. 8 (1986), incorporated herein byreference.

As used herein, “pharmaceutically acceptable carrier,” “carrier,” and“excipient” may be used interchangeably, and refer to any inert andpharmaceutically acceptable material that has substantially nobiological activity, and makes up a substantial part of the formulation.

As used herein, the terms “administration,” and “administering” refer tothe manner in which an active agent is presented to a subject.Administration can be accomplished by various art-known routes such asoral, parenteral, transdermal, inhalation, implantation, etc.

The term “pulmonary administration” represents any method ofadministration in which an active agent can be administered through thepulmonary route by inhaling an aerosolized liquid or powder form(nasally or orally). Such aerosolized liquid or powder forms aretraditionally intended to substantially release and or deliver theactive agent to the mucosal membrane and epithelium of the lungs. In thecontext of this disclosure, the active agent is in powder form.

The term “nominal load” or “total load” refers to the total amount offormulation packaged or partitioned for administration to a subject. Forexample, the nominal load is the total amount of powder formulation thatis enclosed in a capsule for use with an inhaler.

The term “nominal dose” or “total dose” refers to the total amount ormass of active agent packaged or partitioned for administration to asubject. For example, the nominal dose is the total amount of activeagent that is enclosed in a capsule for use with an inhaler.

The term “emitted dose” (ED(%)) refers to the mass of an active agentthat is emitted from a dry powder inhaler aerosolization device as apercentage of a nominal dose mass.

Powder that exhibits high flow rate often results in higher ED(%).

The term “fine particle fraction” or “fine particle fraction from theemitted dose” (% FPF(ED)) refers to the mass of active agent having anaerodynamic diameter below about about 5 μm as a percentage of anemitted dose mass. Typically, the cutoff size is less than or equal toan aerodynamic diameter of about 5 μm but, depending on the experimentalconditions, can be around 6.4 μm. The FPF is often used to evaluate theefficiency of aerosol deaggregation.

The term “respirable fraction” (RF(%)) is the mass of an active agentthat is below a certain aerodynamic cutoff size as a percentage of anominal dose mass. Also known as the fine particle fraction from thetotal dose (FPF(TD)). Fine particle fraction may also be calculated as apercentage of the emitted dose (FPF(ED)). The respirable fractionrepresents the proportion of powder aerosol that can enter the deeprespiratory tract. Typically, the RF cutoff size is an aerodynamicdiameter of less than about 10 μm, preferably less than about 7 μm, andmost preferably less than or about 5 μm. For example, depending on theexperimental conditions, the cutoff size RF can be around 6.4 μm. Therespirable fraction may be determined using an inertial sampling device.

The aerodynamic diameter (D_(ae)) is a spherical equivalent diameter andderives from the equivalence between the inhaled particle and a sphereof unit density (ρ_(o)) undergoing sedimentation at the same rate as perthe following formula:

$\begin{matrix}{D_{ae} = {D_{v}\sqrt{\left( \frac{\rho}{x\;\rho\; o} \right)}}} & \left( {{Eq}.\mspace{14mu} 1} \right)\end{matrix}$

where D_(v) is the volume-equivalent diameter, ρ is the particle densityand χ is the shape factor. Hence, the aerodynamic behavior depends onparticle geometry, density and volume diameter: a small sphericalparticle with a high density will behave aerodynamically as a biggerparticle, being poorly transported in the lower airways. The D_(ae) canbe improved reducing the volume diameter and the density or increasingthe shape factor of the particles, by means of different processes.

The term “mass median aerodynamic diameter” (MMAD) refers to the massmedian aerodynamic diameter of airborne particles at which 50% ofparticles by mass are larger and 50% are smaller. In other words, it isthe median of the aerodynamic particle size distribution as a functionof particle mass. The percentages of mass less than the statedaerodynamic diameters versus the aerodynamic diameters are plottedlogarithmically. The MMAD is taken as the intersection of the line withthe 50% cumulative percent. Computational methods can also be applied.

As used herein, a plurality of items, structural elements, compositionalelements, and/or materials may be presented in a common list forconvenience. However, these lists should be construed as though eachmember of the list is individually identified as a separate and uniquemember. Thus, no individual member of such list should be construed as ade facto equivalent of any other member of the same list solely based ontheir presentation in a common group without indications to thecontrary.

Concentrations, amounts, and other numerical data may be expressed orpresented herein in a range format. It is to be understood that such arange format is used merely for convenience and brevity and thus shouldbe interpreted flexibly to include not only the numerical valuesexplicitly recited as the limits of the range, but also to include allthe individual numerical values or sub-ranges encompassed within thatrange as if each numerical value and sub-range is explicitly recited. Asan illustration, a numerical range of “about 1 to about 5” should beinterpreted to include not only the explicitly recited values of about 1to about 5, but also include individual values and sub-ranges within theindicated range. Thus, included in this numerical range are individualvalues such as 2, 3, and 4 and sub-ranges such as from 1-3, from 2-4,and from 3-5, etc., as well as 1, 2, 3, 4, and 5, individually.

This same principle applies to ranges reciting only one numerical valueas a minimum or a maximum. Furthermore, such an interpretation shouldapply regardless of the breadth of the range or the characteristicsbeing described.

II. Formulations

Provided are dry powder pharmaceutical compositions of PDE5 inhibitorsand pharmaceutically acceptable salts and esters thereof. Thecompositions include at least about 2% by weight of active agent and atleast one pharmaceutically acceptable carrier.

In one aspect, provided is a powder pharmaceutical compositioncomprising a) at least about 2% by weight of a PDE5 inhibitor or apharmaceutically acceptable salt or ester thereof relative to the totalweight of the overall pharmaceutical composition, and b) at least onepharmaceutically acceptable carrier. In one aspect, the PDE5 inhibitormay be at least one of vardenafil, sildenafil, tadalafil, avanafil,benzamidenafil, lodenafil, mirodenafil, udenafil, or zaprinast, or apharmaceutically acceptable salt or ester thereof. In one aspect, thecomposition may include at least about 2% to about 20% by weight of thePDE5 inhibitor. In one aspect, the composition may include at leastabout 2% to about 20% by weight of vardenafil or a pharmaceuticallyacceptable salt or ester thereof. In one aspect, the at least onepharmaceutically acceptable carrier may include lactose, mannitol,trehalose, or starch. In one aspect, the at least one pharmaceuticallyacceptable carrier may include at least one of a mono-, di- orpoly-saccharide, or their derivatives, calcium stearate, magnesiumstearate, leucine or its derivatives, lecithin, human serum albumin,polylysine, polyarginine, or other force control agents, or combinationsthereof. In one aspect, the PDE5 inhibitor or a pharmaceuticallyacceptable salt or ester may be micronized. In one aspect, thecomposition may be packaged to have a nominal load of about 3 mg to 30mg. In one aspect, the composition may be packaged to have a nominaldose of at least about 0.25 mg. In one aspect, the composition may bepackaged to have a delivered dose of at least about 0.075 mg.

In one aspect, provided is a method of aerosolizing a powderpharmaceutical composition comprising a) at least 2% by weight of a PDE5inhibitor, or a pharmaceutically acceptable salt or ester thereof,relative to the total weight of the overall pharmaceutical composition,and b) at least one pharmaceutically acceptable carrier, the methodcomprising: providing an inhaler comprising a dispersion chamber havingan inlet and an outlet, the dispersion chamber containing an actuatorthat is movable reciprocatable along a longitudinal axis of thedispersion chamber; and inducing air flow through the outlet channel tocause air and the powder pharmaceutical composition to enter into thedispersion chamber from the inlet, and to cause the actuator tooscillate within the dispersion chamber to assist in dispersing thepowder pharmaceutical composition from the outlet for delivery to asubject through the outlet. In various aspects, the powderpharmaceutical composition may have one or more of the propertiesrecited in the previous paragraph. In one aspect, the composition mayhave a mass median aerodynamic diameter of between 0.5 μm and 5 μm uponaerosolization. In one aspect, the composition may have a fine particlefraction of at least about 20% upon aerosolization. In one aspect, thecomposition may have an emitted dose of at least about 40% uponaerosolization. In one aspect, the powdered medicament may be storedwithin a storage compartment (of the inhaler), and wherein the powderpharmaceutical composition is transferred from the storage compartment,through the inlet and into the dispersion chamber. In one aspect, theinlet may be in fluid communication with an initial chamber, and whereinthe powder pharmaceutical composition is received into the initialchamber prior to passing through the inlet and into the dispersionchamber.

In one aspect, provided is a method of treating a disease in a subjectin need thereof, the method comprising administering to the subject viaa pulmonary route an effective amount of a powder pharmaceuticalcomposition comprising a) at least about 2% of a PDE5 inhibitor, or apharmaceutically acceptable salt or ester thereof, by weight relative tothe total weight of the overall pharmaceutical composition dose, and b)at least one pharmaceutically acceptable carrier. In one aspect, thedisease may be a lung disease or a heart disease. For example, in someaspects, the lung disease may be pulmonary arterial hypertension orcystic fibrosis. In other aspects, the heart disease may be congestiveheart failure. In various aspects, the powder pharmaceutical compositionmay have one or more of the properties recited in the previousparagraphs. In one aspect, the powder pharmaceutical composition may beadministered as an aerosol. In another aspect, the powder pharmaceuticalcomposition may be administered using a dry powder inhaler or a metereddose inhaler. For example, in some aspects, the powder pharmaceuticalcomposition may be administered by providing an inhaler comprising adispersion chamber having an inlet and an outlet, the dispersion chambercontaining an actuator that is movable reciprocatable along alongitudinal axis of the dispersion chamber; and inducing air flowthrough the outlet channel to cause air and the powder pharmaceuticalcomposition to enter into the dispersion chamber from the inlet, and tocause the actuator to oscillate within the dispersion chamber to assistin dispersing the powder pharmaceutical composition from the outlet fordelivery to a subject through the outlet. In one aspect, a delivereddose of about 0.25 mg to about 20 mg may be delivered to the subjectupon aerosolization.

Active Agents

In one aspect, the active agent of the pharmaceutical composition may aPDE5 inhibitor. Examples of PDE5 inhibitors include, but are not limitedto, vardenafil, sildenafil, tadalafil, avanafil, benzamidenafil,lodenafil, mirodenafil, udenafil, zaprinast, or any of theirpharmaceutically acceptable salts, esters, or derivatives. In oneaspect, the active agent may be vardenafil, in all of its suitableforms, which has the formula (I):

The compound of Formula (I) is chemically identified as2-[2-ethoxy-5-(4-ethylpiperazin-1-yl)sulfonylphenyl]-5-methyl-7-propyl-1H-imidazo[5,1-i][1,2,4]triazin-4-one.Two polymorphic structures have been known for the free base ofvardenafil described by Formula (I) (Form I described in WO/1999/024433and Form II described in U.S. Pat. No. 7,977,478). Vardenafil canfurther form salts, which are described by general chemical Formula(II), wherein HA stands for any acid (as described in WO/2013/075680).The majority of solid forms of vardenafil are the respectivehydrochlorides and their hydrates (as described in U.S. Pat. Nos.6,362,178 and 7,977,478; Haning et al., Bioorg. Med. Chem. Lett. 12(2002) 865-868), which are described by general Formula (III). Thehydrochloride trihydrate (as described in U.S. Pat. Nos. 6,362,178 and8,273,876, WO/2002/050076) described by chemical Formula (IV), is theform of vardenafil that has been used for preparing oral dosage forms(WO/2010/130393, WO/2008/151811, WO/2005/110420, WO/2004/006894). Anamorphous form of vardenafil hydrochloride trihydrate has been described(U.S. Pat. No. 7,977,478), as well as a thermodynamically stablecrystalline form used in preparing dosage forms (U.S. Pat. No.8,273,876). The crystalline hydrate according to Formula (IV) isinstable due to possible loss of crystal water in using this salt forpreparation of a dosage form (U.S. Pat. No. 8,273,876), but also in anyinappropriate manipulation with this salt during its preparation.

For example, the active agent may be vardenafil as shown in Formula (I)(also referred to herein as VarBase), sildenafil, tadalafil, avanafil,benzamidenafil, lodenafil, mirodenafil, udenafil, or zaprinast, as wellas pharmaceutically acceptable, pharmacologically active derivativesthereof, or compounds significantly related thereto, including withoutlimitation, salts, pharmaceutically acceptable salts, N-oxides,prodrugs, active metabolites, isomers, fragments, solvates, includinghydrates, polymorphs, pseudopolymorphs, esters, etc. In some instances,the term “active agent” includes all pharmaceutically acceptable formsof vardenafil or the other PDE5 inhibitors described herein. Forexample, the active agent can be in an isomeric mixture. In addition,the active agent can be in a solvated form such as a hydrate. Any formof the active agent is suitable for use in the compositions of thepresent invention, such as, for example, a pharmaceutically acceptablesalt of the active agent, a free acid of the active agent, or a mixturethereof. In some instances, the term “active agent” may include allpharmaceutically acceptable salts, derivatives, esters, and analogs ofvardenafil or the other PDE5 inhibitors listed herein, as well ascombinations thereof.

In some aspects, the active agent may be a vardenafil compound havingthe chemical forms as set forth in Formulas (I), (II), (III), or (IV)above. For example, the pharmaceutically acceptable salts of vardenafilmay include, without limitation, hydrogen chloride salt forms thereofand the like. For example, where the vardenafil salt (VarSalt) ishydrogen chloride, the mono-hydrogen chloride may be represented byFormulas (II) or (IV). When unhydrated, the mono-hydrogen chloride formmay be represented by Formula (II), also referred to herein as VarHCl.When this form in fully hydrated, it is represented by Formula (IV),also referred to herein as VarHCl.3H₂O. When partially hydrated, it isrepresented by Formula (III), also referred to herein as VarHCl.xH₂O,where “x” represents undetermined amount of bound water between 0-3. Thedi-hydrogen chloride form of vardenafil can be represented by Formulas(II) or (III). When unhydrated, the di-hydrogen chloride form may berepresented by Formula (II), also referred to herein as Var(HCl)₂. Whenhydrated, this form is represented by Formula (III), which is referredto herein as Var(HCl)₂.xH₂O, as this form is unstable and readily loseswater molecules.

In certain aspects, active agent may be present in different crystalforms. The different crystalline forms of the same compound can have animpact on one or more physical properties, such as stability,solubility, melting point, bulk density, flow properties,bioavailability, etc. For example, vardenafil base as shown in Formula(I) has two polymorphic forms.

The solid powder forms of active agent may be characterized by one ormore of several techniques including differential scanning calorimetry(DSC), thermogravimetric analysis (TGA), dynamic vapor sorption (DVS),x-ray powder diffraction (XRPD), and Karl Fischer (KF) titration, and pHtitration. The active agents may also be assessed in liquid form bynuclear magnetic resonance (NMR). Further, combinations of suchtechniques may be used to describe the invention. For example, one ormore XRPD patterns combined with one or more DVS plots may be used todescribe one or more solid forms of the active agents in a way thatdifferentiates them from each other, including the various forms ofdifferent PDE5 inhibitors (such as salts, esters, and hydrates).

Although it characterizes a form, it is not necessary to rely only uponan entire diffraction pattern or spectrum to characterize an activeagent. Those of ordinary skill in the pharmaceutical arts recognize thata subset of a diffraction pattern, spectrum, or plot may be used tocharacterize an active agent provided that subset distinguishes theactive agent from the other forms. Thus, one or more X-ray powderdiffraction pattern alone may be used to characterize an active agent.Likewise, one or more DVS or DSC plots alone may be used to characterizean active agent. Likewise, one or more pH titration analyses may be usedto characterize an active agent. Likewise, one or more NMR spectra alonemay be used to characterize an active agent. Such characterizations aredone by comparing the XRPD, DSC, DVS, TGA, NMR data amongst the forms todetermine characteristic peaks.

One may also combine data from other techniques in such acharacterization. Thus, one may rely upon one or more XRPD pattern and,for example, one or more NMR spectrum, HPLC trace, DSC and/or DVS plot,TGA data, Karl Fischer analyses, or pH analyses, to characterize anactive agent. For example, if one or more X-ray diffraction peakcharacterizes an active agent, one could also consider HPLC, DSC, DVS,TGA, NMR, KF titration, and pH titration data to characterize the activeagent. In particular, combining multiple techniques for analysis of anactive agent forms can be advantageous to confirm chemical identity ofthe active agent.

For example, as shown in Table 2, HPLC analysis combined with KarlFischer titration can identify the chemical forms of vardenafil asVar(HCl)₂.xH₂O and not VarHCl.xH₂O. In some instances, elementalanalysis of carbon, hydrogen, and nitrogen can identify differentchemical forms of vardenafil based on their molecular formulas. Forexample, for VarBase and vardenafil HCl salts (VarSalts) and hydrates,the following equations may be used:

$\begin{matrix}{{Water}\mspace{14mu}{equation}\text{:}\mspace{14mu}\frac{18y}{488.6 + {36.5y} + {18x}}} & \left( {{Eq}.\mspace{14mu} 2} \right) \\{{CHN}\mspace{14mu}{equation}\text{:}\mspace{14mu}\frac{488.6 - 64 - 32 - x + {2y}}{488.6 + {36.5y} + {18x}}} & \left( {{Eq}.\mspace{14mu} 3} \right)\end{matrix}$

where y is the number of HCl molecules bound to the vardenafil moleculeand x is the number of water molecules bound to the vardenafil molecule.For other salts, the equations may be modified to account for theelements of the salt. In another example, NMR analysis may be performedto identify chemical shifts characteristic of different vardenafilforms. The NMR analysis may be either ¹H NMR analysis or ¹³C NMRanalysis as shown in FIG. 1 and FIG. 2. In some instances, d₆-DMSO canbe used as a solvent. For example, by ¹H NMR analysis, VarHCl.3H₂O canbe identified by a methyl peak shifted to 2.472 ppm and triplet(doublet+singlet) around 8 ppm as shown in FIG. 1. In another example,by ¹H NMR analysis, Var(HCl)₂.xH₂O can be identified by a methyl peakshifted to 2.604 ppm and a quintet (triplet+doublet) around 8 ppm asshown in FIG. 1.

In some instances, active agents may be characterized and distinguishedusing DSC as shown in FIGS. 8A-8C. For example, Var(HCl)₂.xH₂O may becharacterized by a onset of glass transition at about 50° C. that endedat about 110° C., a small endothermic peak at about 140° C., and twolarge endothermic peaks at 222° C. and 294° C. In another example,VarBase may be identified by a heat of fusion temperature of 190° C.,with an onset temperature of about 177° C. when the scanning rate wasset at 10° C./min, and degradation peaks when the temperature is raisedabove 250° C. In some instances, the melting temperature of thevardenafil forms as determined by DSC may identify different forms ofVarBase. In another example, VarHCl.xH₂O may be identified by a largeendothermic peak at 107° C., and onset temperature of about 50-60° C.,and a heat of fusion temperature of about 199° C. In other instances,active agents may be characterized and distinguished using DVS as shownin FIGS. 9A-9D, TGA as shown in FIG. 10, and XRPD as shown in FIGS.11A-11C.

Excipients

The disclosed dry powder compositions can additionally include acarrier/excipient. Dry powder compositions may contain a powder mix forinhalation of the active ingredient and a suitable powder base (acarrier, a diluent, and/or an excipient substance) such as mono-, di orpoly-saccharides (for example, lactose, mannitol, trehalose, or starch).In certain cases, the carrier may form from about 1% to about 95% byweight of the formulation. In some instances, the powder base may act asa carrier, a diluent that aids in dispensing the active agent, and afluidizing agent to assist dispersion of the active agent.

In some instances, lactose may be a suitable powder base for use withPDE5 inhibitor dry powder compositions. In some instances, lactose is asuitable carrier for vardenafil formulations for pulmonaryadministration because it does not react with vardenafil as shown, forexample, in FIGS. 5A-5D for VarHCl.3H₂O. In some cases,vardenafil-lactose blends are chemically stable even though lactose is areducing sugar that could react via a Maillard chemical reaction withthe amines in vardenafil. The lactose may be, for example, alpha-lactosemonohydrate, anhydrous alpha-lactose, anhydrous beta-lactose, or a blendthereof (for example, 70-80% anhydrous beta-lactose and 20-30% anhydrousalpha-lactose). In some instances, lactose (or other powder base) may besieved, milled, micronized, or some combination thereof. The lactose maycomprise a fine lactose fraction. The fine lactose fraction is definedas the fraction of lactose having a particle size of less than 7 μm,such as less than 6 μm, for example less than 5 μm. The particle size ofthe fine lactose fraction may be less than 4.5 μm. The fine lactosefraction, if present, may comprise 2% to 50% by weight of the totallactose component, such as 5% to 10% by weight fine lactose, for example4.5% by weight fine lactose. In some cases, lactose of different sizefractions may be combined in a dry powder composition. In someinstances, the particle size of the carrier will be much greater thanthat of the active agent. For example, the lactose (or other powderbase) may have average diameter of between about 2 μm to about 250 μm,more preferably about 5 μm to about 150 μm, or more preferably about 60μm to about 90 μm. These sizes can be determined by laser diffractionobtaining an equivalent volume diameter, or by other sizing methods suchas sieving.

The disclosed dry powder compositions may also include, in addition tothe active ingredient and carrier, a further excipient (a ternary agent)such as a mono-, di or poly-saccharides and their derivatives, calciumstearate or magnesium stearate, leucine and its derivatives, lecithin,human serum albumin, polylysine, polyarginine, and other force controlagents. In some instances, if magnesium stearate is present in thecomposition, it may be present in an amount of about 0.2% to 2%, such as0.6% to 2% or 0.5% to 1.75%, or 0.6%, 0.75%, 1%, 1.25% or 1.5% w/w,based on the total weight of the composition. The magnesium stearate mayhave a particle size in the range 1 μm to 50 μm, and more particularly 1μm to 20 μm.

Alternatively, in some instances, the dry powder composition containspure active agent, without any carriers or excipients.

Dosage Forms

In one aspect, the disclosed compositions may take the form of drypowders suitable for pulmonary administration via inhalation.

Dry powder dosage forms of PDE5 inhibitors (such vardenafil, sildenafil,tadalafil, avanafil, benzamidenafil, lodenafil, mirodenafil, udenafil,or zaprinast, or pharmaceutically acceptable salts or esters thereof)and a pharmaceutically acceptable carrier as described herein offeradvantages over other traditional formulations for oral administration(such as tablets, capsules, and liquids administered by swallowing). Forexample, administration by inhalation of the dry powder formulationovercomes the dosing limitations of oral administrations because higherconcentrations of the active agent can be delivered to the site ofaction (lungs) without the side effects seen with systemicadministration. Similarly, administration by inhalation may even allowthe use of these agents in patients who are unable to tolerate thesedrugs because of hypotension, drug interactions in the liver or othersystemic adverse effects, including systemic toxicities associated withchronic daily use, which arise with traditional dosage forms for oraladministration.

As used herein, the term “dosage form” refers to physically discreteunits suitable as unitary dosages for human subjects and other mammals,each unit containing a predetermined quantity (nominal dose) oftherapeutic agent calculated to produce the desired onset, tolerability,and therapeutic effects, in association with one or more suitablepharmaceutical excipients such as carriers. Methods for preparing suchdosage forms are known or will be apparent to those skilled in the art.The dosage form to be administered will, in any event, contain aquantity of the therapeutic agent in a therapeutically effective amountfor relief of the condition being treated when administered inaccordance with the teachings of this disclosure.

In some instances, the disclosed compositions may comprise from about 2%to about 100%. In some instances, about 2%, about 3%, about 4%, about5%, about 10%, about 15%, about 20%, about 25%, about 30%, about 35%,about 40%, about 45%, about 50%, about 55%, about 60%, about 65%, about70%, about 75%, about 80%, about 85%, about 90%, about 95%, or about100% by weight of the active agent may be used (in whatever chosenform). In some cases, the compositions comprise about 5% to about 50%,or about 2% to about 20% by weight of the active agent. One skilled inthe art understands that the foregoing percentages will vary dependingupon the particular source of active agent utilized, the amount ofactive agent desired in the final formulation, and the aerosolperformance of the final formulation.

In some instances, the compositions may comprise at least about 2% byweight of the active agent, such as, for example, at least about 2% toabout 20% by weight of the active agent. For example, as shown in Tables6-8, the concentration of the active agent may be 5% to 20% in drycompositions with an acceptable carrier for pulmonary administration(such as lactose). In other instances, the concentration of active agentmay be greater than 20%. For example, as shown in FIG. 15A, the activeagent concentration may be anywhere from 20% to 100% active agent. Forexample, in some instances, the composition may 100% pure active agent,or nearly 100% pure active agent as shown, for example, in Table 5. Incertain instances, for example as shown in FIG. 15A, the emitted dose ofa composition upon aerosolization may decrease as the concentration ofactive agent increases. In some cases, this may be due to deposition ofthe active agent onto the inhaler device used for aerosolization asshown, for example in FIG. 15B. However, this may vary based on theconfiguration of the inhaler device used for aerosolization.

In another aspect, the dry powder formulation may exhibit long termstability. In some instances, this is in contrast to vardenafil inaqueous solutions, which may be more prone to acidic, basic, oroxidative degradation as shown in FIGS. 4A-4F. For example, the drypowder compositions may be stored to reduce the possibility of eitherdehydration or exposure to moisture in the air. The compositions mayalso be stable when stored at room temperature. For example, thecomposition may be stable at room temperature for at least 1 month, orat least 3 months, or at least 6 months as shown in FIGS. 5A-5D. In someinstances, the composition may be stable at room temperature for about 1year or about two years. In some instances, the dry powder compositioncontain primarily pure active agent. In other instances, the dry powdercomposition may contain at least 50%, such as, for example, at least90%, pharmaceutically acceptable carrier/excipient. In some instances,the excipient may include lactose.

The disclosed dry powder compositions are generally aerosolizable forthe purposes of administration as a dry powder dispersion. Suitabledevices for aerosolization include dry powder inhaler and metered doseinhalers. Such devices function to emit a dispersion of the formulationcontained within the device. The characteristics of the emitteddispersion, particularly the aerosol performance of the composition, areproperties that relate in part to the dry powder composition.

Preparation of Dry Powder Formulations

Any suitable methods can be used to mix the formulation comprising theactive agent as described, for example, in Remington: The Science andPractice of Pharmacy, 25^(th) Edition. In some instances, the activeagent and carrier are combined, mixed and the mixture may be directlypackaged for aerosolization (such as in a capsule). In certaininstances, the active agent and carrier are combined and mixed using themethod of geometric dilution as generally known in the art. In oneaspect, disclosed is a method of producing a powder pharmaceuticalcomposition comprising the active agent, by contacting at least about 2%of the active agent by weight relative to the total weight of theoverall pharmaceutical composition with at least one pharmaceuticallyacceptable carrier. In some instances, the active agent may be a PDE5inhibitor, such as vardenafil, or a pharmaceutically acceptable salt,ester, or solvate thereof as described herein. In some instances, theactive agent may be at least about 2% by weight of the composition, orsome other amount as described above.

Active ingredients for administration by inhalation generally have acontrolled particle size. The optimum particle size for inhalation intothe bronchial system is usually 1-10 preferably 1-5 Particles having asize above 20 μm are generally too large when inhaled to reach the smallairways. To achieve the desired particle size for the active agent, thecompound as produced may be size reduced by conventional means, such asby micronization. Micronization of the active agent or of allformulation components can be performed using any suitable commerciallyavailable apparatus such as those described in Remington: The Scienceand Practice of Pharmacy, 25^(th) Edition. For example, micronizationmay be performed by air-jet micronization, spiral milling, controlledprecipitation, high-pressure homogenization, spray drying, orcryo-milling. The desired fraction may be separated out by airclassification or sieving. Preferably, the active agent particles willbe crystalline. In some instances, the active agent alone can bemicronized prior to mixing. In some instances, as shown in FIGS. 6A-6Cand summarized in Table 3, vardenafil compounds may be micronized withinthe respirable range. For example, the D_(V50) of the micronizedparticles may be between about 1 μm and about 2 μm with a span of about0.25 to about 1.6.

In certain cases, it may be desirable to increase the particle size ofthe active agent (for example, after micronization), which can beperformed, for example, by granulation.

In some aspects, mixing is performed by agitating the components of thedry powder formulations to produce a mixture having a uniformconcentration of active agent. For example, the components may becombined and then mixed such as by a low shear or high shear blenderand/or agitated at high speed using a mechanical mixer. In someinstances, the components may be mixed at an agitation speed of about 20rpm, about 50 rpm, or about 100 rpm. In some instances, the componentsare mixed at an agitation speed of about 99-100 rpm. The componentsshould be mixed for a sufficient time to ensure uniformity of the blend.For example, the components may be mixed for at least 5 min, 10 min, 15min, or 20 min. In some instances, after an initial mixing step, blenduniformity of the mixture may be assessed and, if necessary, the mixturemay be agitated for an additional period of time until the desired blenduniformity is achieved. Blend uniformity may be assessed as thecoefficient of variation for samples assessed throughout the mixture. Insome instances, the dry powder composition after mixing has acoefficient of variation of no more than about 5% or, in some instances,no more than about 10%. In one example, as shown in FIG. 12, a 5% blendof Var(HCl)₂.xH₂O and lactose had a blend uniformity (% coefficient ofvariation) less than about 5% when mixed for about 5-20 min at about 100rpm.

Following mixing, a relaxation or de-energizing step may be performed toallow the powder blend to discharge built up electrostatic charges fromhandling. This step may involve incubation at a certain temperature fromroom temperature to near 50° C. for a predetermined time from 1 day to30 days, or exposure to a controlled humidity air source for acontrolled time period, or some other method of charge dissipationcommonly known. Alternatively, an ionizing source that producesapproximately equal amounts of positive and negative ions may be used todissipate charge.

Once the dry powder composition is obtained, it may be packaged intoindividual doses suitable for administration via inhalation. Theformulation may be transferred into individual doses using a dosingsystem that is commonly used to fill capsules, blister cavities,reservoirs, and containers. Following filling of the doses, the powderis ready for dosing from an inhaler device. In some instances, theformulation may be packaged in a blister dose containment system. Forexample, capsule material may include a gelatin or HPMC(hydroxypropylmethylcellulose) capsule dose containment system. Ingeneral, the capsules may each contain one dose, or multiple capsulescan be used to contain the equivalent of one dose. Examples ofcommercial dry powder inhaler products where the powder is stored incapsules include the FORADIL® Aerolizer®, the SPIRIVA® HandiHaler®, andthe VENTOLIN® Rotahaler (GSK). In some instances, the formulation may bepackaged in individual blisters, where one blister may contain one dose.Examples of commercial dry powder inhaler products where the powder isstored in blister dose containment systems include the FLOVENT® Diskus®,SEREVENT® Diskus®, and the ADVAIR® Diskus®. In some instances, theformulation may be packaged into a reservoir, where a particularreservoir may contain sufficient powder for multiple doses. Examples ofcommercial dry powder inhaler products where the powder is stored inreservoirs include the ASMANEX® Twisthaler®, SYMBICORT® Turbuhaler® andthe Budelin® Novolizer®. Still other embodiments are possible. In someinstances, the composition may be packaged to have a nominal load ofabout 3 mg to 30 mg. Based on the aerosol performance properties andconcentration of the active agent in the dry powder composition, thecomposition may be packaged to have a delivered dose of at least about0.1 mg to about 20 mg, or at least about 0.25 mg to about 20 mg, or atleast about 0.5 mg to about 10 mg, or at least about 0.1 mg, about 0.25mg, 0.5 mg, about 1 mg, about 5 mg, about 10 mg, about 15 mg, or about20 mg. In some instances, the composition may be packaged to have adelivered dose of about 0.25 mg to 20 mg, including delivered doses inthe range of about 0.25 mg to about 5 mg, about 0.25 mg to about 2 mg,about 0.25 mg to about 3 mg, about 0.25 mg to about 4 mg, about 1 mg toabout 5 mg, about 2 mg to about 8 mg, about 2 mg to about 12 mg, andabout 5 mg to about 15 mg.

III. Methods of Administration

The compositions disclosed herein are useful in therapeuticapplications, such as for treating pulmonary hypertension, cysticfibrosis, and congestive heart failure. Importantly, the compositions ofthe present invention provide the rapid and predictable delivery of anactive agent in the lungs that should increase the bioavailability ofthe active agent, overcoming the limitations of oral dosing and reducingrisk of drug interactions and systemic side effects. In particular, thedelivery of the therapeutic agent optimizes absorption within the lungs.As a result, the therapeutic agent can reach the site of action locallyin the lung, or in systemic circulation, in a substantially shorterperiod of time and at a substantially higher local lung concentrationthan with traditional oral (for example, tablet) administration. Also,as elevated oral doses may be associated with increased systemic sideeffects, administration of the dry powder composition via the pulmonaryroute may permit higher concentrations of active agent to beadministered than with oral administration.

In addition, the dry powder compositions disclosed herein offeradvantages over compositions for oral administration. In particular,vardenafil exhibits a good balance between lipophilicity (relativelylow) and solubility (relatively high), which is desirable for a drypowder formulation for pulmonary delivery to facilitate cellular uptake,lung residence time, and metabolism within the airways. An advantage ofinhaled compositions over oral dosage forms may be the short time untileffects are observed. The short onset of action can be important formany diseases. Another advantage of dry powder formulations forinhalation is avoiding metabolism in the liver and side effectsassociated therewith at high concentrations of active agent.

Administration of the compositions disclosed herein is preferablycarried out via any of the accepted modes of pulmonary administration,particularly oral dry powder inhalation. In some instances, thecomposition may be administered through the mouth or through the nasalpassages. Suitable devices for administration of the dry powdercomposition include dry powder inhalers and metered dose inhalers.

FIG. 13 is a block diagram illustrating methods for aerosolizing suchdry powder compositions according to certain aspects. As a first step1301 of the method 1300, a powder pharmaceutical composition comprisinga) at least 2% by weight of a PDE5 inhibitor, or a pharmaceuticallyacceptable salt or ester thereof, relative to the total weight of theoverall pharmaceutical composition, and b) at least one pharmaceuticallyacceptable carrier may be provided. Step 1302 illustrates that aninhaler comprising a dispersion chamber having an inlet and an outlet,the dispersion chamber containing an actuator that is movablereciprocatable along a longitudinal axis of the dispersion chamber maybe provided. Steps 1301 and 1302 may be performed in any order orsimultaneously. As shown in step 1303, air flow is induced through theoutlet channel to cause air and the powder pharmaceutical composition toenter into the dispersion chamber from the inlet, and to cause theactuator to oscillate within the dispersion chamber to assist indispersing the powder pharmaceutical composition from the outlet fordelivery to a subject through the outlet. In some instances, thepowdered medicament may be stored within a storage compartment (of theinhaler), and wherein the powder pharmaceutical composition istransferred from the storage compartment, through the inlet and into thedispersion chamber. In certain cases, the inlet may be in fluidcommunication with an initial chamber, and wherein the powderpharmaceutical composition is received into the initial chamber prior topassing through the inlet and into the dispersion chamber.

In practice, a patient may prime an aerosolization device by puncturingthe container holding the formulation (such as a capsule or blister)that is contained within a powder reservoir, or the patient may transferdrug from the powder reservoir into the inhalation portion of thedevice, and then inhale. Inhalation by a patient draws the powderthrough the inhaler device where powder entrainment results in dilation,fluidization, and at least the partial de-agglomerating of powderaggregates and micro aggregates and then dispersion of the API powderaerosol (in other words, aerosolization). This approach may be usefulfor effectively dispersing both pure drug-powder formulations wherethere are no carrier particles are present and traditional binary orternary carrier-based formulations.

Exemplary devices for use in administering the dry powder compositioninclude dry powder inhalers and metered dose inhalers such as, but notlimited to Twisthaler® (Merck), Diskus® (GSK), Handihaler® (BI),Aerolizer®, Turbuhaler® (AstraZeneca), Flexhaler® (Astrazeneca),Neohaler® (Breezhaler®) (Novartis), Easyhaler® (Orion), Novolizer® (MedaPharma), Rotahaler® (GSK), and others. As known to those skilled in theart, difference devices will have different performance characteristicsbased on the device resistance, deaggregation mechanisms, adhesion ofdrug to the internal flow channels, ability of the patient to coordinateand inhale, among other factors.

In another aspect, the dry powder compositions may be administered usinga dry powder inhaler or a metered dose inhaler that comprises a drypowder deaggregator, also referred to as a powder dispersion mechanism.Exemplary powder dispersion mechanisms are described in U.S. PatentPublication Nos. 2013/0340754 and 2013/0340747, which are incorporatedherein by reference in their entirety. In some instances, such powderdispersion mechanisms may comprise of a bead positioned within a chamberthat is arranged and configured to induce a sudden, rapid, or otherwiseabrupt expansion of a flow stream upon entering the chamber. In general,the chamber may be coupled to any form or type of dose containmentsystem or source that supplies powdered active agent into the chamber.Referring now to FIG. 14A, a cross-section of an example tubular body100 having an inlet 102 and a dispersion chamber 104 is shown accordingto the principles of the present disclosure. In this example, a fluid(air) flow path of the inlet 102 is defined by a first internal diameter106, and a fluid (air) flow path of the chamber 104 is defined by asecond internal diameter 108. Although shown approximately constant inFIG. 14A, at least one of the first internal diameter 106 and the secondinternal diameter 108 may vary in dimension as defined with respect to alongitudinal axis L of the tubular body 100. In addition to providingdesirable fluid flow characteristics, as discussed further below, theseconfigurable dimensions may be defined such as to provide for a draftangle for injection molding.

For example, referring now additionally to FIG. 14B, a bead 302 may bepositioned within the chamber 104 of the tubular body 100 of FIG. 14A.In this example, the bead 302 may be approximately spherical, at leaston the macroscale, and oscillate in a manner similar to that describedin U.S. Pat. No. 8,651,104, which is herein incorporated by reference inits entirety. Further, a relationship between the diameter 304 of thebead 302, the first internal diameter 106 of the inlet 102, and thesecond internal diameter 108 of the chamber 104 may be as described inU.S. Patent Publication Nos. 2013/0340754 and 2013/0340747, which areincorporated herein by reference in their entirety.

In some instances, the powder dispersion mechanism may be coupled to adry powder inhaler or metered dose inhaler such as a commerciallyavailable device. The dispersion mechansim (dispersion chamber) may beadapted to receive an aerosolized powdered active agent from an inletchannel such as described, for example, in U.S. Patent Publication Nos.2013/0340754, which is incorporated herein by reference in its entirety.The powder dispersion mechanism (dry powder deaggregator) may be adaptedto receive at least a portion of the aerosolized powdered active agentfrom the first chamber of the inhaler. The powder dispersion mechanismmay include a dispersion chamber that may hold an actuator that ismovable within the dispersion chamber along a longitudinal axis. The drypowder inhaler may include an outlet channel through which air andpowdered active agent exit the inhaler to be delivered to a subject. Ageometry of the inhaler may be such that a flow profile is generatedwithin the dispersion chamber that causes the actuator to oscillatealong the longitudinal axis, enabling the oscillating actuator toeffectively disperse powdered medicament received in the dispersionchamber for delivery to the patient through the outlet channel.

In one example, the powder dispersion mechanism may have an inletdiameter of about 2.72 mm and an oscillation chamber length and diameterof about 10 mm and about 5.89 mm, respectively. In some instances, thepowder dispersion mechanism may include a bead having a diameter of 4 mmin the chamber. In some instances, the bead may have a density of about0.9 mg/mm³. In some instances, the bead may be made of polypropylene ora similar material. In some instances, the powder dispersion mechanismcan be coupled with a commercial inhaler or other component to form adelivery system for aerosolization of the dry powder compositions. Insome cases, the delivery system may work at effectively at differentairflow rates and pressure drops within the range of normalphysiological inhalation for a subject such as, for example, about 40 toabout 60 L/min and about 2 to about 4 kPa.

In certain instances, a dry powder inhaler system may be used toaerosolize and administer the dry powder formulation. The dry powderinhaler system may include a receptacle containing an amount of powderedactive agent. The dry powder inhaler system may include an inlet channelthat is adapted to receive air and powdered active agent from thereceptacle. The dry powder inhaler system may include a first chamberthat is adapted to receive air and powdered active agent from the inletchannel. A volume of the first chamber may be greater than volume of theinlet channel. The dry powder inhaler system may include a dispersionchamber that is adapted to receive air and powdered medicament from thefirst chamber. The dispersion chamber may hold an actuator that ismovable within the dispersion chamber along a longitudinal axis. The drypowder inhaler system may include an outlet channel through which airand powdered active agent exit the dispersion chamber to be delivered toa patient. A geometry of the system may be such that a flow profile isgenerated within the system that causes the actuator to oscillate alongthe longitudinal axis, enabling the oscillating actuator to effectivelydisperse powdered medicament received in the dispersion chamber fordelivery to the patient through the outlet channel.

In one aspect, a method for aerosolizing a powdered medicament isdisclosed. The method may include providing an inhaler comprising afirst chamber, and a dispersion chamber, the dispersion chambercontaining an actuator that is movable within the dispersion chamberalong a longitudinal axis, and an outlet channel. The method may includeinducing air flow through the outlet channel to cause air and powderedmedicament to enter into the first chamber through the inlet channelinto the dispersion chamber, and to cause the actuator to oscillatewithin the dispersion chamber to effectively disperse powderedmedicament passing through the first chamber and the dispersion chamberto be entrained by the air and delivered to the patient through theoutlet channel.

Several different parameters are used as measures of the aerosolperformance of a dry powder formulation under certain airflow andpressure drop conditions. For example, the emitted dose” (ED(%)) of aformulation refers to the mass of an active agent that is emitted from adry powder inhaler aerosolization device as a percentage of a nominaldose mass. Powder formulations that exhibit better powder flowproperties often result in higher ED(%). Another parameter is therespirable fraction (RF(%)) of the formulation, which is the mass of anactive agent that is below a certain aerodynamic cutoff size as apercentage of a nominal dose mass. Fine particle fraction is the mass ofactive agent having an aerodynamic diameter below about about 5 μm as apercentage of an emitted dose mass. This response is often used toevaluate the efficiency of aerosol deaggregation. For example, the %FPF(ED) may be the percentage of an active agent of a formulation havingan aerodynamic diameter at or below about 5 μm. The respirable fractionrepresents the proportion of powder aerosol active agent that can enterthe deep respiratory tract. Another parameter is mass median aerodynamicdiameter (MMAD). The MMAD is the median of the distribution of airborneparticle mass with respect to the aerodynamic diameter. Airflowconditions are generally selected to span the range of physiologicalinhalation capabilities of a subject. For example, for a human subject,the pressure drop for an inhalation may be in the range of about 0.5 kPato about 8 kPa, more typically within the range of about 1 kPa to about4 kPa, and including airflow rates of about 5 L/min to about 120 L/min,more typically in the range of about 15 L/min to about 100 L/min.

In some instances, the dry powder composition may have an emitted doseof at least about 20%, about 25%, about 30%, about 35%, about 40%, about50%, about 55%, about 60%, about 65%, about 70%, about 75%, about 80%,about 85%, about 90%, or about 95% upon aerosolization. In one example,as shown in Table 5, pure active agent compositions may have an emitteddose of at least about 65% for VarBase, at least about 25% forVar(HCl)₂.xH₂O, at least about 70% for Var(HCl)₂.xH₂O (rehydrated), andat least about 40% for VarHCl.xH₂O. In some cases, the active agent maybe micronized. In some instances, nominal dose may not impact emitteddose of pure active agent compositions. In another example, as shown inTables 6-8, dry powder compositions of vardenafil compounds plus acarrier, such as lactose, may have emitted doses that are, on average,somewhat higher than the pure active agent compositions. For example, a5% Var(HCl)₂.xH₂O composition may have an emitted dose of at least about75% regardless of whether the nominal load used for aerosolization was10 mg or 20 mg as shown in Table 6. In another example, 5% and 20%Var(HCl)₂.xH₂O compositions may have an emitted dose of at least about80% as shown in Table 7. In another example, 5% and 20% VarBase andVarHCl.xH₂O compositions may have emitted doses of at least about 70% asshown in Table 8.

In certain cases, the dry powder composition may have a fine particlefraction of at least about 20%, about 25%, about 30%, about 35%, about40%, about 50%, about 55%, about 60%, about 65%, about 70%, about 75%,about 80%, about 85%, about 90%, or about 95% upon aerosolization. Insome instances, composition of pure active agent may have a fineparticle fraction of at least about 20% as shown in Table 5. Forexample, as shown in Table 5, pure active agent compositions may have anemitted dose of at least about 35-60% for VarBase, at least about 85-90%for Var(HCl)₂.xH₂O, at least about 60-65% for Var(HCl)₂.xH₂O(rehydrated), and at least about 65-70% for VarHCl.xH₂O. In some cases,a composition of a vardenafil compound and a carrier (such as lactose)may have a fine particle fraction of at least about 40-50% as shown inTables 6-8. For example, a 5% Var(HCl)₂.xH₂O composition may have a fineparticle fraction of at least about 65-70% regardless of whether thenominal load used for aerosolization was 10 mg or 20 mg as shown inTable 6. In another example, 5% and 20% Var(HCl)₂.xH₂O compositions mayhave a fine particle fraction of at least about 65-80% as shown in Table7. In some instances, increasing the concentration of active agent (suchas Var(HCl)₂.xH₂O) in the composition may increase the fine particlefraction upon aerosolization. In another example, 5% and 20% VarBase andVarHCl.xH₂O compositions may have a fine particle fractions of at leastabout 40-70% as shown in Table 8. In some instances, increasing theactive agent (such as VarBase and VarHCl.xH₂O) in the composition mayincrease the fine particle fraction upon aerosolization. In someinstances, VarHCl.xH₂O has a slightly higher respirable fraction uponaerosolization than VarBase.

In certain cases, the dry powder composition may have a respirablefraction of at least about 20%, about 25%, about 30%, about 35%, about40%, about 50%, about 55%, about 60%, about 65%, or about 70%, uponaerosolization. In one example, as shown in Table 5, pure active agentcompositions may have a respirable fraction of at least about 25% or 45%for VarBase depending on nominal dose (10 mg vs 3 mg), at least about20% for Var(HCl)₂.xH₂O (regardless of nominal dose, 10 mg vs 3 mg), atleast about 45% for Var(HCl)₂.xH₂O (rehydrated), and at least about 30%for VarHCl.xH₂O. In some cases, the active agent may be micronized. Inanother example, a 5% Var(HCl)₂.xH₂O composition may have a respirablefraction of at least about 50% regardless of whether the nominal loadused for aerosolization was 10 mg or 20 mg as shown in Table 6. Inanother example, 5% and 20% Var(HCl)₂.xH₂O compositions may have arespirable fraction of at least about 50-60% as shown in Table 7. Insome instances, increasing the concentration of the active agent maydiminish the respirable fraction of the composition (such asVarHCl.xH₂O) upon aerosolization. In another example, 5% and 20% VarBaseand VarHCl.xH₂O compositions may have respirable fractions of at leastabout 25-50% as shown in Table 8. In some instances, increasing theconcentration of the active agent (such as VarBase and VarHCl.xH₂O) maydiminish the respirable fraction of the composition upon aerosolization.

In some instances, the MMAD of the composition is less than about 10 μm,less than about 5 μm, or less than about 3 μm, upon aerosolization. Forexample, upon aerosolization, the compositions may have a mass medianaerodynamic diameter (MMAD) of between about 0.5 μm and about 8 μm, suchas, for example, between about 1 μm and about 2 μm, between about 1 μmand about 3 μm, between about 0.5 μm and about 4 μm, or between about0.5 μm and about 5 μm, or other ranges therein. In some instances, asshown in Tables 6-7 and 9, the composition may have a relatively smallMMAD of about 0.7 to about 1.5 μm, including about 0.7 μm to about 1. 5μm, about 0.8 μm to about 0.85 μm, about 0.8 μm to about 0.95 μm, andabout 0.9 μm to about 1.2 μm.

In certain cases, the dry composition formulations may have similaraerosolization properties at both high and low airflow rates. This mayreduce variability in dosing (due to inhalation variability). Forexample, as shown in Table 9, a 5% Var(HCl)₂.xH₂O composition hassimilar emitted dose and respirable fraction upon aerosolization at both2 kPa and 4 kPa airflow using a dry powder inhaler.

Upon inhalation, some portion of the dry powder composition,particularly the active agent, is emitted from a delivery system, suchas an inhaler, upon aerosolization of the dry powder composition.Generally, the term delivered dose refers to the percentage mass emitteddose (ED(%)) as a function of the nominal dose mass in the deliverysystem. In some instances, upon aerosolization and inhalation, thecomposition may have a delivered dose of about 0.25 mg to 20 mg,including delivered doses in the range of about 0.25 mg to about 5 mg,about 0.25 mg to about 2 mg, about 0.25 mg to about 3 mg, about 0.25 mgto about 4 mg, about 1 mg to about 5 mg, about 2 mg to about 8 mg, about2 mg to about 12 mg, and about 5 mg to about 15 mg. In some instances,upon aerosolization, the composition may have a delivered dose of atleast about 0.1 mg to about 20 mg, or at least about 0.25 mg to about 20mg, or at least about 0.5 mg to about 10 mg, or at least about 0.1 mg,about 0.25 mg, 0.5 mg, about 1 mg, about 5 mg, about 10 mg, about 15 mg,or about 20 mg.

One issue relating to use of inhalers for pulmonary administration ofdry powder composition is that, in some instances, depending on themechanism by which the inhaler components operate (for example, thecapsule piercing mechanism), an amount of the composition may bedeposited within the device and not emitted. For example, as shown inFIGS. 15A and 15B, deposition of active agent increased approximatelylinearly as active agent concentration increased for one type of drypowder inhaler.

In some instances, the dry powder composition is formulated and packagedto have substantial delivered (emitted) dose uniformity. The uniformityof the emitted dose reflects the safety, quality, and efficacy of thedry powder compositions. In some instances, the composition may have adelivered dose uniformity of about 75% to about 125% target dose over2-60 inhalations.

The percent recovery (% recvy) is a way to check the mass balance beforeand after dose delivery by capturing and measuring the amount of drugdischarged from an inhaler to verify accuracy of analysis. In someinstances, the total mass of drug collected in all of the componentsdivided by the total number of minimum recommended doses discharged isnot less than 75% and not more than 125% of the average minimumrecommended dose determined during testing for delivered-doseuniformity. See USP <601>. In some instances, the percent recovery ofthe dry powder formulation is at least about 95% or at least about 100%,for example, as shown in Table 5 and Table 8, for various drycompositions with different active agents and concentrations and nominalloads.

IV. Methods of Treatment

The compositions disclosed herein have particular utility in the area ofhuman and veterinary therapeutics. In one aspect, a method of treating adisease in a mammal in need thereof is provided, the method comprisingadministering to the mammal via a pulmonary route an effective amount ofa powder pharmaceutical composition comprising a) at least about 2% of aPDE5 inhibitor, or a pharmaceutically acceptable salt or ester thereof,by weight relative to the total weight of the overall pharmaceuticalcomposition dose, and b) at least one pharmaceutically acceptablecarrier. The dry powder formulations and methods described hereinprovide improved methods of treating certain diseases that are currentlytreated only with oral formulations that are swallowed. In someinstances, the disease may be a lung disease such as pulmonaryhypertension or cystic fibrosis. For example the lung disease may bepulmonary arterial hypertension. In some cases, the disease may be aheart disease. For example, the heart disease may be congestive heartfailure/disease.

PDE5 inhibitors are used to augment the action of endogenous nitricoxide resulting in vasodilatation and reduction of smooth muscleproliferation in patients with pulmonary hypertension. Pulmonaryhypertension includes, but is not limited to, pulmonary arterialhypertension, primary pulmonary hypertension, secondary pulmonaryhypertension, familial pulmonary hypertension, sporadic pulmonaryhypertension, precapillary pulmonary hypertension, pulmonary arteryhypertension, idiopathic pulmonary hypertension, thrombotic pulmonaryarteriopathy, plexogenic pulmonary arteriopathy and pulmonaryhypertension associated with or related to, left ventriculardysfunction, mitral valvular disease, constrictive pericarditis, aorticstenosis, cardiomyopathy, mediastinal fibrosis, anomalous pulmonaryvenous drainage, pulmonary venoocclusive disease, collagen vasculardisease, congenital heart disease, congenital heart disease, pulmonaryvenus hypertension, chronic obstructive pulmonary disease, interstitiallung disease, lung fibrosis, sleep-disordered breathing,alveolarhyperventilation disorder, chronic exposure to high altitude,neonatal lung disease, alveolar-capillary dysplasia, sickle celldisease, other coagulation disorders, chronic thromboemboli, connectivetissue disease, lupus, schistosomiasis, sarcoidosis or pulmonarycapillary hemangiomatosis.

Cystic fibrosis is caused by a defective or missing CFTR proteinresulting from mutations in the CFTR gene. There are more than 1,800 TheF508del mutation, results in a “trafficking” defect, in which the CFTRprotein does not reach the cell surface in sufficient quantities. Theabsence of working CFTR proteins results in poor flow of salt and waterinto and out of cells in a number of organs, which results in a thick,sticky mucus that builds up and blocks the airways of in the lungs,causing chronic lung infections, inflammation and progressive lungdamage. While cystic fibrosis is caused by mutations in the CTFR gene,cGMP has a key role in the cell and regulates many aspects of properCFTR functioning. cGMP is metabolized by the PDE5 enzyme. Thus, in someinstances, PDE5 inhibitors may maintain and control levels of cGMP,which, in turn, may modulate CFTR and improve CTFR function. PDE5inhibitors have also been shown to exhibit anti-inflammatory andanti-pseudomonal activity in preclinical models. (Poschet et al. 2007Lung Cell. Molec. Physiol. 293(3):L712-L719) For example, oralsildenafil, a PDE5i, has reduced biomarkers of lung inflammation inclinical trials in adult CF patients with F508del mutation.(Taylor-Cousar et al., Abstract A94, Therapeutic & Diagnostic Adv.Cystic Fibrosis 2013, p. A2066.)

PDE5 expression appears to be increased in a number of myocardialdisease states, including chronic myopathies involving myocyte orventricular hypertrophy. (Schwartz et al. 2012 JACC 59(1):9-15) Inhypertrophied myocardium, PDE5 inhibitors increase cGMP, which inhibitsphosphodiesterase-3 and thereby increases cyclic adenosinemonophosphate.(cAMP). cAMP in turn activates protein kinase A, whichincreases intracellular calcium and contractility (Schwartz). PDE5inhibitors were found to improve hemodynamic and clinical parameters inpatients with congestive heart disease in a number of small trials(Schwartz). Small trials in patients with congestive heart diseasedemonstrated the greatest benefit of PDE5Is in patients with secondaryPAH and right ventricular failure (Lewis et al. 2007 Circulation116:1555-1562; Melenovsky et al. 2009 J. Am. Coll. Cardiol.54:595-600.).

In some cases, the delivery of dry powder formulations of PDE5inhibitors may be more efficient that oral dose formulations by creatinga high local lung concentration of the active agent, potentiallyyielding a quicker onset of action with likely comparable or enhancedefficacy with fewer side effects.

Local delivery of PDE5i directly into the lung may circumvent poor oralbioavailability and provide even greater selectivity of effect bydelivering high local lung concentrations with lower total dose exposurewith the potential for greater efficacy. Administration of dry powderformulations via inhalation are also advantageous because the route ofadministration allows avoidance of extensive first pass hepaticmetabolism and drug-drug interaction with CYP3A inducers/inhibitors.Many drugs used to treat lung diseases (such a cystic fibrosis andpulmonary hypertension) can be metabolized using this enzyme system and,therefore, are susceptible to interactions or contraindications.Inhalation delivery may avoid the severity of these interactions becauseavoidance of first pass metabolism, while the lower administered dose(but higher lung tissue dose) may minimize the potential forinteractions. Inhalation delivery may also avoid adverse side effectsassociated with orally administered PDE5 inhibitor formulations, such ashypotension, hearing or visual improvement, headache, dyspepsia,flushing, insomnia, erythema, dyspnea, rhinitis, diarrhea, myalgia,pyrexia, gastritis, sinusitis, paraesthesia. For example, in manychronic obstructive pulmonary disease (COPD) patients,ventilation/perfusion (V/Q) mismatch may preclude the use of oral PDE5inhibitor formulations as these patients generally have some degree ofhypoxic vasoconstriction that can be worsened by the action of PDE5inhibitors and other adverse effects, particularly in patients withmoderately severe COPD. In some instances, a dry powder PDE5 inhibitorformulation with low oral and throat deposition and swallowing maybetter target the active agent to the ventilated areas of the lung,controlling the pulmonary hypertension while avoiding increasing V/Qmismatch and hypoxia. Thus, in some instances, administration of PDE5inhibitors via a pulmonary route may be useful for treating subjects whoare unable to tolerate clinically useful doses of oral formulationsbecause of hypotension, drug interactions or other systemic adverseeffects.

In some instances, lower doses of dry powder formulations (as comparedto oral doses for swallowing) may be administered to a subject. In someinstances, similar doses of the dry powder formulations as used for oraldoses for swallowing may be administered to a subject, wherein, becausethe drug is administered directly to the target site, there may be areduction in systemic drug levels using a dry powder inhalerformulation. This may lead to a reduction of systemic toxicitiesassociated with chronic daily use (headache, lowered blood pressure,cardiovascular effects anterior ischemic optic neuropathy, priapism,vaso-occlusive crises.

In general, orally administered PDE5 inhibitors dissolve in thedigestive tract and are absorbed into the blood stream. Upon reachingthe pulmonary circulation, the PDE5 compound diffuses across thevascular endothelium into the surrounding smooth muscle cells, where itinhibits the PDE5 enzyme present in the intracellular fluid of themuscle cells, resulting in a dilatory effect on the pulmonary arteriesand arterioles. In contrast, in some instances, inhaled powderformulation of PDE5 inhibitors are expected to take a more direct routeafter deposition in the lumen of pulmonary airways, diffusing across theairway walls into the vascular smooth muscle cells where it acts on thePDE5 enzyme and may result in a dilatory effect on the pulmonaryarteries and arterioles. Thus, in some instances, for example, in thecontext of pulmonary hypertension, the target area of the lung forpowder delivery is the deep lung where the pulmonary vasculature hassmooth muscle cells upon which the active agent can exert itspharmacological effects. In some instances, effective delivery to thisarea of the lung may require smaller aerodynamic particle size ranges(typically greater than 1 micron on average, for example, between 1-5microns MMAD, or between about 1-3 microns MMAD) for the aerosolizedactive agent. In other instances, for example, in the context of cysticfibrosis, the target tissue is the airway epithelial (such as theciliated airways), particularly those affected by defective CFTRprotein. In some instances, effective delivery to this area of the lungmay require aerodynamic particle size ranges of between about 1 to about5 microns in aerodynamic diameter, about 2 to about 6 microns. or about2 to about 7 microns. In some instances, the dry powder formulationsprovided in this disclosure have an MMAD in the appropriate size rangefor delivery to the deeper parts of the lung.

In some instances, pulmonary delivery with higher aerosolizationefficiencies (such as, for example, about 70% FPF), may allow less mouthand throat deposition upon aerosolization and inhalation by a subject.As mouth and throat deposited drug is swallowed and will be absorbedsimilarly to orally administered formulation, reducing swallowing byachieving efficient aerosolization may reduce the incidence of systemiceffects.

In certain instances, a delivered dose of about 0.25 mg to about 20 mgmay be delivered to the subject upon aerosolization. For example, insome instances, typical doses for treatment of pulmonary hypertensionwill be about 0.5 mg to about 20 mg of active agent, depending onpatient disease category, disease stage, and other health aspects of thesubjects such as, for example, medication, patient age, etc. In someinstances, the inhaled dose required to attain efficacy in a humansubject with pulmonary hypertension delivered via a high efficiencyinhaler device may be about 1/10th to 1/20th the oral dose, or 0.25 mgto 0.5 mg, possibly 0.1 mg to 3 mg of active agent delivered to the deeplung. In another example, in some instances, typical doses for treatmentof cystic fibrosis will be about 0.5 mg to about 30 mg of active agent,depending on patient genetic factors (such as type of CTFR mutation),disease stage, and other health aspects of the subjects suhc as, forexample, medication, patient age, etc. For example, in some instances,typical doses for treatment of myocardial diseases will be about 0.5 mgto about 20 mg of active agent, depending on patient disease category,disease stage, and other health aspects of the subjects such as, forexample, medication, patient age, etc.

FIG. 16 is a block diagram illustrating methods of treating a disease ina mammal in need thereof according to some aspects. As shown in step1801 of method 1800, a subject with a disease in need of treatment isprovided. In one aspect, the disease may be a lung disease or a heartdisease. For example, in some aspects, the lung disease may be pulmonaryhypertension or cystic fibrosis. In other aspects, the heart disease maybe congestive heart failure. As shown in step 1802, the method furtherincludes administering to the subject via a pulmonary route an effectiveamount of a powder pharmaceutical composition comprising a) at leastabout 2% of a PDE5 inhibitor, or a pharmaceutically acceptable salt orester thereof, by weight relative to the total weight of the overallpharmaceutical composition dose, and b) at least one pharmaceuticallyacceptable carrier. In some instances, the powder pharmaceuticalcomposition may be administered as an aerosol. For example, in somecases, the powder pharmaceutical composition may be administered using adry powder inhaler or a metered dose inhaler. For example, in someinstances, the powder pharmaceutical composition may be administered byproviding an inhaler comprising a dispersion chamber having an inlet andan outlet, the dispersion chamber containing an actuator that is movablereciprocatable along a longitudinal axis of the dispersion chamber; andinducing air flow through the outlet channel to cause air and the powderpharmaceutical composition to enter into the dispersion chamber from theinlet, and to cause the actuator to oscillate within the dispersionchamber to assist in dispersing the powder pharmaceutical compositionfrom the outlet for delivery to a subject through the outlet.

The foregoing description of certain aspects and features, includingillustrated embodiments, has been presented only for the purpose ofillustration and description and is not intended to be exhaustive or tolimit the disclosure to the precise forms disclosed. Numerousmodifications, adaptations, and uses thereof will be apparent to thoseskilled in the art without departing from the scope of the disclosure.Certain features that are described in this specification in the contextof separate embodiments can also be implemented in combination in asingle implementation. Conversely, various features that are describedin the context of a single implementation can also be implemented inmultiple ways separately or in any suitable subcombination. Moreover,although features may be described above as acting in certaincombinations, one or more features from a combination can in some casesbe excised from the combination, and the combination may be directed toa subcombination or variation of a subcombination. Thus, particularembodiments have been described. Other embodiments are within the scopeof the disclosure.

The following examples are intended for illustration only, are notintended to limit the scope of this disclosure. The contents of all U.S.patents and other references referred to in this application are herebyincorporated by reference herein in their entirety.

EXAMPLES Example 1. Identification of Vardenafil Compounds

In view of the range of vardenafil forms, including salts and hydrates,as well as the limitation of conventional chemical identificationmethods, it is not straightforward to identify the form of vardenafilsold commercially or described in the art. For example, both anhydrousVarHCl (vardenafil hydrochloride) and Var(HCl)₂ (vardenafildihydrochloride) can stoichiometrically obtain 1-3 bound water moleculesto form hydrates. Among them, crystalline VarHCl.3H₂O is thethermodynamically stable form that has been used in commercialformulations. However, VarHCl and Var(HCl)₂ can be difficult todifferentiate from each other by each individual analytical method suchas high performance liquid chromatography (HPLC), ultravioletspectrophotometer (UV), mass spectroscopy (MS), Infra-red (IR),elemental analysis (CHN) and chloride ion analysis. For example, themolecular weight of Var(HCl)₂.H₂O (579.55 g/mol) and VarHCl.3H₂O (579.12g/mol) are nearly identical. As such, differentiating between thesemolecules by any individual mass related analytical techniques reliablymay not be possible. In fact, Applicants have found that severalreputable chemical suppliers have mistakenly sold Var(HCl)₂.xH₂O(vardenafil dihydrochloride hydrate) as VarHCl.3H₂O (vardenafilhydrochloride trihydrate).

Testing methods were developed to ensure the ability to identify anddifferentiate the chemical identity of vardenafil forms for use inpreparation of formulations. As described further below, the methodsare: HPLC quantification coupled with Karl Fischer (KF) titration(Section A), elemental analysis (C, H, N) coupled with KF (Section B),NMR CH and ¹³C) (Section C), and pH titration assessment (Section D).For example, as shown below, these methods were used to differentiateVar(HCl)₂.xH₂O and VarHCl.xH₂O.

A. HPLC Quantification Coupled with Karl Fischer (KF) Titration

While HPLC columns can be used to separate vardenafil compounds (activepharmaceutical ingredients; APIs) based on their polarity, this is nothow HPLC was used to characterize the vardenafil compounds. Theprinciple of this method is that the HPLC area under the curve (AUC) forthe vardenafil portion of VarHCl and Var(HCl)₂ are the same as VarBase(488.61 g/mol) when the same mass of compounds are compared. The H⁺ andCl⁻ ions in the vardenafil compounds will not be detected and reflectedin AUC. Thus, when the same mass of the vardenafil compounds are weighedand analyzed by HPLC, the values of AUC quantified by HPLC will showVarBase>VarHCl >Var(HCl)₂ because part of the mass (H⁺ and Cl⁻) inVarHCl and Var(HCl)₂ will not contribute to the AUC, as shown below inTable 1. By comparing the AUC ratio of VarHCl/VarBase orVar(HCl)₂/VarBase, the number of HCl in vardenafil salts can bedetermined. Karl Fischer titration was performed using coulometrictitration to determine trace amounts of water in the sample.

TABLE 1 Exemplary Vardenafil Forms and Theoretical Water ContentSubstance MW (g/mol) % VarBase Water (%) VarBase 488.61 100.0 0 VarHCl525.07 93.1 0 VarHCl•H₂O 543.09 90.0 3.32 VarHCl•2H₂O 561.10 87.1 6.42VarHCl•3H₂O 579.12 84.4 9.33 Var(HCl)₂ 561.54 87.0 0 Var(HCl)₂•H₂O579.55 84.3 3.11 Var(HCl)₂•2H₂O 597.57 81.8 6.03 Var(HCl)₂•3H₂O 615.5979.4 8.78

There are four assumptions for applying this method:

-   -   1) All APIs are 100% pure.    -   2) The API dry weight (anhydrate VarHCl and Var(HCl)₂) is used        for the mass calculation. This requires dehydration of raw        material by heating in vacuo.    -   3) If there are any residual water contents (both unbound and        bound water), they can be accurately quantified by KF.    -   4) The HPLC method (column, mobile phase, buffer, etc.) does not        change throughout the testing.

HPLC analysis was performed using an Agilent 1260 Infinity series moduleHPLC system with appropriate columns and buffers (acidic aqueous andacidic organic mobile phases). The column temperature was maintained at40° C. and the detection was monitored at a wavelength of 215 nm.

VarBase and a vardenafil salt hydrate (VarSalt) were purchased andanalyzed using the above-described method. The results are shown inTable 2. Based on the dry weight and AUC, the amount of vardenafil inthe salt is 87.2% of that in VarBase. This is consistent with thepercent API of Var(HCl)₂, which is calculated to have a percent API of87.1% as shown in Table 1 above. Thus, although the VarSalt was claimedto VarHCl.3H₂O, this analysis shows that the compound was actuallyVar(HCl)₂.xH₂O.

TABLE 2 HPLC + KF Analysis of VarSalt and VarBase VarSalt VarBase APIWeight (mg) 3.002 3.008 Water Content (%) 3.485 1.658 API Dry Weight(mg) 2.897 2.958 Diluent Volume (mL) 20 20 API Concentration (mcg/mL)144.9 147.9 AUC 4707.8 5509.1 AUC/mcg/mL 32.5 37.2 AUC/mcg/mL ratio0.872 N/A (VarSalt/VarBase)

B. Elemental Analysis of C, N, and H Coupled with Karl Fischer (KF)Titration

Elemental analysis can determine the mass fraction of carbon, hydrogen,nitrogen and other heteroatoms (generally referred to as CHNX). The mostcommon elemental analysis accomplished by combustion analysis is forcarbon, hydrogen, nitrogen, which is referred to herein as CHN analysis.Commercial VarSalt was purchased for this analysis. The amount of waterin the vardenafil compound was also accurately determined by KFtitration before the CHN analysis was performed to ensure accuracy. Theelemental analysis showed a % C value of 45.88, a % H value of 5.92 anda % N value of 13.87, within an error margin of ±0.3%. The water contentwas measured using a coulometric KF titrator, and the result was 6.92%.Based on this analysis, the VarSalt appeared to have approximately 2 HClmolecules and 2 water molecules, indicating that the VarSalt was likelyVar(HCl)₂.2H₂O (or possibly a mixture of dihydrate and trihydrateforms).

C. Nuclear Magnetic Resonance (NMR) (¹H and ¹³C)

VarHCl.3H₂O and Var(HCl)₂.xH₂O (VarHCl and Var(HCl)₂ in solution) havegenerally been deemed as indistinguishable using NMR. For example, U.S.Pat. No. 6,362,178 describes that the chemical shift for VarHCl.3H₂O(Example 20) and Var(HCl)₂.xH₂O (Example 337) are identical by ¹H NMR,as set forth below.

-   -   200 MHz ¹H-NMR (DMSO-d₆) 0.96, t, 3H; 1.22, t, 3H; 1.36, t, 3H,        1.82, sex, 2H; 2.61, s, 3H; 2.88, m, 2H; 3.08, m, 6H; 3.50, m,        2H; 3.70, m, 2H; 4:25, quart., 2H; 748, d, 1H; 7.95, m, 2H,        11.42, s, 1H; 12.45, s, 1H.        This is problematic because many vendors provide only the ¹H NMR        in the Certificate of Analysis for vardenafil and, thus, may not        be correctly distinguishing between VarHCl.3H₂O and        Var(HCl)₂.xH₂O.

To identify spectral characteristics that could be used to identifyVarHCl.3H₂O and Var(HCl)₂.xH₂O, both ¹H and ¹³C NMR were performed. Thespectra are shown in FIG. 1. The results showed that VarHCl.3H₂O (top)and Var(HCl)₂.xH₂O (bottom) can be readily distinguished from NMR, usingd₆-DMSO as solvent. For example, in the ¹H NMR, a characteristic methylpeak showed a chemical shift of 2.472 ppm for VarHCl.3H₂O, while thesame methyl peak shifted to 2.604 ppm for Var(HCl)₂.xH₂O. De-shieldingcauses a methyl group shift from 2.472 to 2.604. At around 8 ppm, two ofthe three protons in the benzene ring of vardenafil showed a triplet(doublet+singlet) for VarHCl.3H₂O, while the same protons showed aquintet (triplet+doublet) for Var(HCl)₂.xH₂O.

The result of ¹³C NMR clearly shows that the chemical shift of a largenumber of carbon signals at different ppm. Spectra for ¹³C NMR ind₆-DMSO analysis of Var(HCl)₂.xH₂O (top) and VarHCl.3H₂O (bottom) areshown in FIG. 2.

This is the first reporting of differences in the NMR spectrum ofVarHCl.3H₂O and Var(HCl)₂.xH₂O. This method can be used, alone or inconjunction with other analytical methods to identify and characterizevardenafil compound preparations. For example, based on this analyticalmethod, it is apparent that the vardenafil salt described in U.S. Pat.No. 6,362,178 (Example 20) is misidentified and is actuallyVar(HCl)₂.xH₂O.

D. pH Titration

Perhaps the easiest way to distinguish Var(HCl)₂, VarHCl, and VarBase isby means of pH titration analysis. The experiment was performed atambient condition (22.5° C. and 31% RH). One gram of Var(HCl)₂.xH₂O wasdissolved in 15 mL pure H₂O in a beaker. NaOH solution (10%) was addedin 20 μL stepwise increments while the solution was stirred vigorously.The pH and temperature was recorded 20 sec after each addition of NaOHsolution. The results of this analysis are shown in FIG. 3.

The result showed that the initial pH was 2.15 at 22.5° C. The pHincreased slowly until precipitation appeared. The pH droppedaccordingly when VarHCl was gradually preciptated from the solutionuntil the pH reached 3.9. A rapid increase in pH was observed,indicating all VarHCl was precipitated. The pH reached a plateau at 5.2and dropped to 4.6, indicating the conversion of VarHCl to VarBase. AllVarBase was precipitated when a sharp change of pH occurred from 5.3 to10.9. Continued addition of 10% NaOH resulted in the dissolution of allprecipitate and the conversion of VarBase to the sodium salt ofvardenafil (NaVar). Thus, in addition to being useful for chemicalidentification purposes, pH titration can also be used for theconversion and preparation of desired salt forms of vardenafil.

Example 2. Intrinsic Stability Assessment of Vardenafil Compounds

The intrinsic stability of vardenifil compounds can be assessed to aidin identification of suitable conditions for preparation ofpharmaceutically acceptable formulations. Characterization of thedegradation pathways for vardenafil compounds provides informationuseful to the development of pharmaceutically acceptable formulationsfor long term storage. Described below are exemplary experimentsrelating to characterization of VarHCl.3H₂O.

Materials: VarHCl.3H₂O, HPLC grade water, 36.5% HCl, NaOH pellets, 6%H₂O₂ were all purchased. 1N HCl and 1N NaOH were prepared in house.

Method: VarHCl.3H₂O, HPLC grade water, 36.5% HCl, NaOH pellets, 6% H₂O₂were all purchased, and 1N HCl and 1N NaOH were prepared in house.Intrinsic stability testing was performed according to InternationalConference on Harmonization (ICH) Guidance for Industry Q1A(R2)Stability Testing of New Drug Substances and Products (November 2003,Rev. 2). Briefly, the compound was tested for acid hydrolysis (1N HCl)and base hydrolysis (1N NaOH) at r.t. for 48 hr and at 60° C. for 4 hr.Oxidation assessment (6% H₂O₂) was performed at r.t. for 48 hr. Thestability of VarHCl.3H₂O in solution was assessed using HPLC analysis asdescribed above in Example 1, Section A.

Starting material (control): The HPLC trace for the starting materialshowed single peak as expected (R_(T)=6.050 min; Area %=100). See FIG.4A.

Degradation in acidic solution: In 1N HCl at r.t. after 48 hr, a singledegradation peak (R_(T)=1.006 min; Area %=2.630) was observed. A similardegradation peak was observed in 1N HCl at 60° C. for four hours(R_(T)=0.998 min; Area %=2.843). The degree of degradation wascomparable in both acidic conditions. The HPLC traces for theseexperiments are shown in FIG. 4B (48 hr at r.t.) and FIG. 4C (4 hr at60° C.).

Degradation in basic solution: In 1N NaOH at r.t. after 48 hr, a majordegradation peak (R_(T1)=1.000 min; Area %=58.692) was observed andcorresponded with four additional small degradation peaks (R_(T)2=0.776;Area %=0.1115; R_(T)3=1.351; Area %=0.055; R_(T)4=2.839; Area %=0.048).When exposed in 1N NaOH 60° C. condition for 4 hrs, a similardegradation pattern was observed: a major degradation peak (R_(T1)=0.992min; Area %=62.652) and corresponded with four additional smalldegradation peaks (R_(T)2=0.778; Area %=0.193; R_(T)3=1.342; Area%=0.071; R_(T)4=2.774; Area %=0.046). The HPLC traces for theseexperiments are shown in FIG. 4D (48 hr at r.t.) and FIG. 4E (4 hr at60° C.).

Degradation in oxidative solution: In 6% H₂O₂ at r.t. for 48 hr, therewere two major and eight minor degradation peaks. The two major peakswere at R_(T)1=1.067 min; Area %=60.270 and R_(T)2=4.862 min; Area%=19.496. The eight minor peaks were at R_(T)3=1.339 min; Area %=0.231;R_(T)4=1.814 min; Area %=0.454; R_(T)5=2.469 min; Area %=0.353;R_(T)6=3.458 min; Area %=0.523; R_(T)7=6.486 min; Area %=1.409;R_(T)8=7.197 min; Area %=0.272; R_(T)9=7.594 min; Area %=0.087;R_(T10)=9.176 min; Area %=0.574. The HPLC traces for these experimentsare shown in FIG. 4F.

These studies showed that VarHCl.3H₂O demonstrated degradation inacidic, basic, and oxidative conditions per ICH Guidance. The extent ofdegradation was significant in basic and oxidative conditions, which isunderstandable because the sulfonamide group in VarHCl.3H₂O issusceptible to hydrolysis, particularly in basic condition. The tertiaryamine group may easily form amine oxide in oxidative condition and theamine oxide may undergo further degradation via a host of chemicalreactions. These observations differ from literature reports on thedegradation of VarHCl.3H₂O (Rao et al, Chromatographia 2008, 68,829-835, showing less extensive degradation in basic conditions).Similarly, it is expected that VarBase could also be oxidized moreeasily when the free tertiary amine is presented in the molecule.

The observed degradation patterns of VarHCl.3H₂O in aqueous solutionsuggest that the development of a dry powder aerosol formulation may bedesirable to maintain chemical stability of the compound. As notedabove, no dry powder aerosol formulations of vardenafil compounds havebeen developed to date.

Example 3. Excipient Compatability Assessment of Vardenafil Compounds

Studies were performed to assess the chemical compatibility/stability ofvardenafil compounds with excipients. The testing of vardenafilcompounds with one or more pharmaceutically acceptableexcipients/carriers is an aspect of developing apharmaceutically-acceptable, stable, carrier-based vardenafilformulation. One of the most frequently used excipients for dry powderaerosol formulation is lactose. However, lactose is a reducing sugar.Vardenafil contains amine groups that could react with lactose via theMaillard reaction. In the absence of prior studies assessing thevardenafil and reducing sugar compatibility, the following experimentswere performed to assess if lactose could be used to prepare a stablevardenafil blend formulation.

A. Materials and Methods

Var(HCl)₂.xH₂O and VarBase were purchased, and VarHCl.3H₂O was preparedin house using Var(HCl)₂.xH₂O. Conversion of Var(HCl)₂.xH₂O toVarHCl.3H₂O was performed by the pH titration described above in Example1, Section D. Var(HCl)₂.xH₂O was used in micronized form (prepared usinga commercial dry jet-miller) as described in Example 4. VarBase andVarHCl.3H₂O were not micronized. Respitose® ML006 (“ML006”)(DMV-Fonterra Excipients), an inhalation grade lactose, was alsopurchased.

Blending ratios were selected based on powder surface area to ensuresufficient contact between API and excipient. The following blends weremade: Var(HCl)₂.xH₂O: ML006 (1:9), VarBase: ML006 (1:1) and VarHCl.3H₂O:ML006 (1:1). Blends were prepared by geometric dilution preblending byhand, followed by mixing using a commercially available laboratoryshaker-mixer. Where enclosed, blends were pouched using foil to preventmoisture ingress into the powder mixture.

Saturated NaCl and NaBr salt solutions were added separately to twodesiccators to create equilibrium relative humidity of 75% at 40° C. and60% at 25° C. (as described in Greenspan, J. Res. Natl. Bureau Std. —A,Phy Chem 1977, 81A (1), 89-96). Prior to use, the stability chamberswere stored in incubators at preset temperature for at least 24 hr.

Samples were (1) pouched and stored at 25° C. and 60% relative humidity(RH), (2) pouched and stored at 40° C. and 75% RH, and (3) unpouched(exposed to ambient environment) at 40° C. and 75% RH. Samples wereassessed for degradation by HPLC, as described above. Analysis wascompleted for the following time points: Var(HCl)₂.xH₂O blend at sixmonth, VarBase blend at three months, and VarHCl.3H₂O blend at onemonth.

B. Results

None of the samples showed chemical degradation products at any of thetime points. Exemplary HPLC traces for the VarHCl.3H₂O blend at onemonth are shown in FIG. 5A (25/60 pouched), FIG. 5B (40/75 pouched),FIG. 5C (40/75 open), and FIG. 5D (VarHCl.3H₂O control). These resultsestablish the stability of vardenafil-lactose blends as vardenafil wasfound to not undergo degradation when mixed with lactose under stable oraccelerated conditions. This analysis is the first reporting thatlactose appears to be an acceptable excipient for the preparation ofvardenafil solid dosage forms.

Example 4. Particle Size Distribution of Micronized Vardenafil Compounds

Particle size of a dry powder aerosol formulation for administration byinhalation is closely linked to the deposition profile in the airways.Thus, a narrow size distribution allows better targeting of the aerosol.The median respirable particle size range is 0.5 to 5 microns, and morepreferably 1-2 microns.

Var(HCl)₂.xH₂O, VarBase, and VarHCl.3H₂O were purchased and thenmicronized using a commercial dry jet-miller. The jet milling wasachieved using typical jet milling conditions and a single millingprocess. As shown in Example 5, micronization leads to partialdehydration of VarHCl.3H₂O. As such, following micronization and absentrehydration, the compound is designated as VarHCl.xH₂O.

The APIs were dispersed in mineral spirit, and particle size analysiswas performed by laser diffraction using a Microtrac X100 Particle SizeAnalyzer. Particle size span was calculated as

${span} = \frac{D_{{v0}{.9}} - D_{{v0}{.1}}}{D_{{v0}{.5}}}$

where D_(v0.1), D_(v0.5) and D_(v0.9) are 10%, 50% and 90% of the volumesize distributed below the respective values.

The particle size distributions of the micronized APIs are shown in FIG.6A (Var(HCl)₂.xH₂O), FIG. 6B (VarBase), and FIG. 6C (VarHCl.xH₂O) andsummarized in the Table 3 below. All three APIs were easily micronizedinto respirable size range. The particle size distributions weresurprisingly narrow with spans less than 1.6 (VarHCl.xH₂O-0.99,Var(HCl)₂.xH₂O-0.27, VarBase—1.557). These experiments demonstrate thatvardenafil compounds can be micronized to achieve a desirable medianrespirable particle size range with a narrow size distribution. Thus,dry powder formulations of vardenafil may be particularly suited foraerosol administration via inhalation.

TABLE 3 Particle Size Distribution Compound D_(V50) Span VarHCl•xH₂O1.179 0.99 Var(HCl)₂•xH₂O 1.85 0.267 VarBase 1.557 1.557

Scanning electron microscopy (SEM) imaging of the micronized APIs areshown in FIG. 7A (Var(HCl)₂.xH₂O), FIG. 7B (VarBase), and FIG. 7C(VarHCl.xH₂O). The powder was placed on the SEM stub and sputter coatedwith Pd—Au. Particle size distribution shown in SEM matches the laserdiffraction data. The particles form aggregates which are typical formicronized powders via jet-milling.

Example 5. Physicochemical Characterization of Vardenafil Compounds

Several additional methods were used to characterize vardenafilcompounds, including differential scanning calorimetry (DSC),thermogravimetric analysis (TGA), dynamic vapor sorption (DVS), andx-ray powder diffraction (XRPD). These analytical methods can be used toconfirm identification of the vardenafil compound and assist withformulation development.

A. Material and Methods

APIs: Micronized Var(HCl)₂.xH₂O, VarBase, and VarHCl.xH₂O as describedin Example 4 were characterized in these studies.

DSC Analysis: Compounds were deposited in non-hermetic crimped aluminumpan. Thermal properties were assessed using a Q2000 Modulated DSC (TAInstrument, New Castle, Del.). Method: scanning rate 10° C./min from0-350° C.; heating; equilibrate at 0° C. for 4 min; modulation ±0.796°C./min.

DVS Analysis: No DVS results of these APIs have been previouslyreported. Moisture sorption and desorption behavior was assessed using aDVS-Advantage 1 (Surface Measurement Systems, Allentown, Pa.).Experimental parameters: sample % P/Po in a range of 0-80; 5% P/Poincrement, equilibrium criteria, both sorption and desorption.Experiments conducted at 20° C.

XRPD Analysis: XRPD was performed for crystallinity and polymorphic formidentification. Experimental parameters: 2° 2Theta range from 3-40degree, 1° 2Theta degree/min. Experiments conducted at room temperature(ambient).

TGA Analysis: TGA was performed on micronized Var(HCl)₂.xH₂O to assessweight loss on heating. Active agent mass was monitored as it wasexposed to a temperature program in a controlled atmosphere.Experimental parameters: scanning rate at 10° C./min, and temperatureranges from 40-280° C.

B. Results

The results for each of Var(HCl)₂.xH₂O, VarBase, and VarHCl.xH₂O usingeach of these methods are described below.

1. Var(HCl)₂.xH₂O

DSC of micronized Var(HCl)₂.xH₂O is shown in FIG. 8A. Var(HCl)₂.xH₂Oexhibited an onset of glass transition T_(g) ˜50° C. that ended at −110°C. This suggests that the high energy jet-milling process introducedamorphous content in the powder. A small endothermic peak was observedat −140° C. that overlapped with the glass transition. This indicatesthat some trihydrate form was present and underwent partial water loss.Two large endothermic peaks were also observed at 222° C. and at 294° C.The former was the heat of fusion T_(m). The nature of the latter isstill under investigation. The result is similar to the DSC ofVar(HCl)₂.3H₂O shown in U.S. Pat. No. 7,977,478 (FIG. 15) but covered alarger temperature range.

DVS of micronized Var(HCl)₂.xH₂O is shown in FIG. 9A. A criticalrelative humidity was shown at 70% in sorption and 40% in desorption. Insorption phase, there were two step inflection points that occurredaround 30% RH and 70% RH. The first may be a glass transition fromamorphous to crystalline, and the second may reflect the formation oftrihydrate. The desorption phase indicated that the trihydrate form isonly stable in a short humidity range of 50% RH-80% RH. It is possiblethat, when RH is below 40% RH, loss of bound water may occur. Anotherdesorption inflection point occurred around 20% RH. This suggests thatVar(HCl)₂.xH₂O is unstable in normal ambient condition and tends to losebound water. A large hysteresis loop was observed due to the hydrationof Var(HCl)₂.

TGA of micronized Var(HCl)₂.xH₂O is shown in FIG. 10. Based on theobserved tilted curve, Var(HCl)₂.xH₂O started to continuously lose waterabove 40° C. There was a transition at around 220° C. to 240° C. Thiscould be the melting phase when the TGA result was combined with DSCthermogram. Another two transitions (inflection points) occurred around80° C. and 130° C. The water loss upon heating profile is comparable tothat described in U.S. Pat. No. 7,977,478 (FIG. 16).

XRPD of micronized Var(HCl)₂.xH₂O is shown in FIG. 11A. The XRPD ofVar(HCl)₂.xH₂O (x=1, 2, or 3) were previously described in U.S. Pat. No.7,977,478. The peaks of the micronized Var(HCl)₂.xH₂O preparation werecompared to those illustrated in that reference, which indicates thatthe Var(HCl)₂.xH₂O preparation is likely a monohydrate and dihydratemixture.

2. VarBase

DSC of micronized VarBase is shown in FIG. 8B. The VarBase preparationshowed a sharp endothermic peak indicating heat of fusion T_(m)=190° C.The onset temperature was at ˜177° C. when DSC scanning rate was set at10° C./min. When the temperature increased above 250° C., decompositionpeaks were observed. VarBase has two polymorphic forms: Form I and FormII. The Form II polymorph was previously determined to have a heat offusion T_(m)=194° C. (U.S. Pat. No. 7,977,478), which is higher than theT_(m) determined by this analysis. Thus, based on T_(m), this VarBasepreparation appeared to be the Form I polymorph. The Form I polymorphhad previously been characterized by XRPD (WO/2011/079935). The XRPDanalysis of the VarBase preparation confirmed that it is the Form Ipolymorph.

DVS of micronized VarBase is shown in FIG. 9B. The VarBase preparationsorption and desorption phases are much simpler as compared to Var(HCl)₂and VarHCl and their hydration forms, likely because VarBase cannot formhydrates and, thus, cannot for pseudopolymorphs. No obvious hysteresisloop was observed indicating that no hydration occurred. Some minorphase change was observed. This may be due to a small amount ofamorphous content in the preparation caused by mechanical stress duringjet-milling.

XRPD of micronized VarBase is shown in FIG. 11B. The comparison of 2θvalues and % intensity with the crystalline Form I and Form II ofVarBase revealed that the VarBase preparation is mainly crystalline FormI. The 2θ values of the major intensity peaks are: 9.8, 11.2, 12.4,14.2, 15.3, 16.2, 17.1, 18.0, 20.1, 21.6, 23.2, 24.6, 27.3 degree. Thisresult is in good agreement with DSC result.

3. VarHCl.xH₂O

As noted above, VarHCl.3H₂O is thermodynamically stable. However, undercertain conditions (such as micronization), partial dehydration canoccur. This is illustrated in the results described below.

DSC of micronized VarHCl.xH₂O is shown in FIG. 8C. VarHCl.xH₂O had alarge endothermic peak at 107° C. showing the loss of bound water. Theonset temperature was about 50˜60° C. This indicates that VarHCl.xH₂Ocould be susceptible to elevated temperature above 50˜60° C. The heat offusion T_(m) was 199.2° C. Above the heat of fusion temperature, thematerial quickly underwent decomposition. This is the first reporting ofDSC analysis of micronized VarHCl.xH₂O.

DVS of micronized VarHCl.xH₂O in FIG. 9C and FIG. 9D. In FIG. 9C, theY-axis is % w/w H₂O uptake, while in FIG. 9D the Y-axis is molar ratio.Together, these isotherm plots permit a clear understanding ofstoichiometric water sorption and desorption of VarHCl.

In the VarHCl sorption phase, there were two inflection points. A firstwater molecule bound to anhydrous VarHCl at a relative humidity (RH) aslow as 5% to form a monohydrate. This indicated that VarHCl is highlyhygroscopic. Between RH 5-40%, a steady but slower water sorptionoccurred at increasing RH. This was followed by a more rapid wateruptake between 40-60% RH. The sorption phase reached a plateau between60-80% RH when the water content of the molecule reached thestoichiometric trihydrate form. This indicated that VarHCl.3H₂O couldmaintain its integrity (not reaching deliquescence) up to 80% RH.

The quick water uptake at RH as low as 5% and preferential formation ofmonohydrate is presumably caused by different H-bond associations amongthe three water molecules that can bind to VarHCl. The first watermolecule can preferentially form H-bonding with the acidic proton andthe carbonyl group of vardenafil. This six-membered ring structure couldresult in stabilized H-bonding that the following H₂O molecules may nothave. See Scheme 1 below.

In the VarHCl.3H₂O desorption phase, the trihydrate form was maintainedbetween 10-80% RH. Water loss only occurred when RH is lower than 15%,and even more so 10%. These results indicated that VarHCl.3H₂O is athermodynamically stable form and that, once the VarHCl.3H₂O is formed,it is unlikely to lose bound water in normal RH % when the powder ismaintained at room temperature.

XRPD of micronized VarHCl.xH₂O is shown in FIG. 11C. The corresponding20 values of the major intensity peaks are: 5.1, 8.2, 10.3, 10.9, 15.4,16.4, 17.3, 19.9, 20.2, 20.8, 22.4, 23.0, 24.5, 25.1, 26.1, 27.0, 27.9,29.1 degree. The 20 values of the intensity peaks for the micronizedVarHCl.xH₂O were compared to previously reported values from the XRPDanalysis of VarHCl.3H₂O (see, for example, U.S. Pat. No. 8,273,876).This comparison indicated that the micronized compound may lose somecrystallinity due to the jet-milling process as the peaks are not assharp (possibly due to loss of peak intensity due to the creation ofamorphous content).

Example 6. Preparation of Vardenafil Formulations

Having established that lactose was a suitable excipient for vardenafilcompound formulations, several lactose blends were prepared with variousvardenafil compounds described in the previous examples. Mixingconditions were assessed to identify satisfactory blends.

The vardenafil compounds used were: Var(HCl)₂.xH₂O, VarBase, micronizedVarHCl.xH₂O, and micronized VarHCl.3H₂O (rehydrated). Formulations wereprepared using two different lactose carriers, a sieved grade ofalpha-monohydrate lactose with an average particle size of about 50 μm(LAC1) and a fine particle lactose having a particle size distributionDvso below about 5 μm (LAC2).

To break up any large agglomerates and facilitate blending and blendhomogeneity, the micronized APIs and LAC1 were passed through a 250 μmsieve. The API powders were then accurately weighed according to the APIconcentration using a micro balance. The pre-blend (1-5 g) was achievedby geometric dilution of API powder into LAC1. Trituration and gentlestirring with a spatula allowed for a good initial blending condition.The mixtures were then blended with a Turbula® T2C Shaker-Mixer. UVanalysis was performed. The API was detected by UV spectrophotometry.

Various blending speeds were tested to determine what speed resulted inthe best blending uniformity. The rotation speed of the shaker-mixer wascalibrated using a stopwatch to slow (22 rpm), medium (49 rpm), and high(99 rpm) speeds. Blending was stopped at 5 min, 10 min, 15 min, and 20min. At each time point, five accurately weighed samples (0.8-1 mg) fromthe top (2 samples), the bottom (2 samples) and the side (1 sample) ofthe jars were dissolved in 20 mL HPLC grade H₂O solution (H₂O: H₃PO₄=1L:0.2 mL) and measured by UV spectrophotometry. The average concentrationwas analyzed and the relative standard deviation (% RSD) (also referredto as coefficient of variation (% CV) was used to evaluate the accuracyof blend concentration and blending uniformity, respectively. A % CVless than 5% was considered to be good blend uniformity.

An exemplary blending example using 5% Var(HCl)₂.xH₂O and LAC1 is shownin FIG. 12. Blending at high speed (99 rpm) gave the best blendinguniformity. The % CV results were consistently within the range of 5% in5-20 min. In contrast, blending at slow and medium speeds showed apattern of mixing and de-mixing that is not suitable to reproduciblyobtain a homogenous mixture.

Blending at high speed for 20 min generally resulted in an overall goodblending uniformity for all API formulations. If UV analysis indicatedthat % CV was greater than 5% in any instances, formulations were mixedfor an additional 10-20 min high speed to reduce the % CV to less than5%.

Using the conditions outlined above, the formulation blends listed inTable 4 were prepared with satisfactory blend concentration and blenduniformity

TABLE 4 Formulation Blends Var(HCl)₂•xH₂O + LAC1 API Concentration:  5%w/w 13% w/w 20% w/w 40% w/w 60% w/w 80% w/w Var(HCl)₂•xH₂O + LAC1 + LAC2Weight Ratio: 20:77:3  20:20:60 VarBase + LAC1 API Concentration:  5%w/w 20% w/w VarHCl•xH₂O + LAC1 API Concentration:  5% w/w (micronizedAPI) 20% w/w VarHCl•3H₂O + LAC1 API Concentration: 20% w/w (micronizedAPI)

Example 7. Aerosol Performance of Vardenafil Formulations

One consideration when formulating a dry powder for inhalation is thatits size should be small enough to permit aerosolization and thedeposition at the appropriate site of the respiratory tract. A failurein deposition may result in a failure of efficacy.

There are several inertia sampling apparatuses that can be used toassess aerosol performance of dry powder formulations. (<601>Aerosols,Nasal Sprays, Metered-Dose Inhalers, and Dry Powder Inhalers Monograph,in USP 29-NF 24 The United States Pharmacopoeia and The NationalFormulary: The Official Compendia of Standards. 2006, The United StatesPharmacopeial Convention, Inc.: Rockville, Md. p. 2617-2636 (“USP<601>”).)

These apparatus classify aerosol particles on the basis of theparticles' aerodynamic diameter. Each stage of the impactor includes asingle or series of nozzles with specific cutoff size. Particles areentrained into the apparatus. Those having sufficient inertia willimpact on that particular stage collection plate, while smallerparticles with insufficient inertia will remain entrained in theairstream and pass to the next stage where the process is repeated. Theaerodynamic size distribution of API can be assessed by collecting thedeposited API mass and the ED %, RF %, FPF % and MMAD (μm) can becalculated from the API deposition pattern. The emitted dose fraction(ED(%); Eq. 4) is determined as the percentage powder mass emitted fromthe initial dosing chamber/capsule relative to the total dose incapsules (nominal dose) (TD). Emitted dose (ED) includes the sum of theAPI mass left on inhaler device and deposited on the device stages. Fineparticle fraction (FPF(%); Eq. 5) is expressed as a percentage of fineparticle dose (FPD) below a certain aerodynamic cutoff size to ED.Respirable fraction (RF(%); Eq. 6) is defined as the percentage of FPDto total dose (TD).

$\begin{matrix}{{{Emitted}\mspace{14mu}{dose}\mspace{14mu}{fraction}\mspace{14mu}\left( {{ED}(\%)} \right)} = {\left( \frac{ED}{TD} \right) \times 100\%}} & \left( {{Eq}.\mspace{14mu} 4} \right) \\{{{Fine}\mspace{14mu}{particle}\mspace{14mu}{fraction}\mspace{14mu}\left( {{FPF}(\%)} \right)} = {\left( \frac{FPD}{ED} \right) \times 100\%}} & \left( {{Eq}.\mspace{14mu} 5} \right) \\{{{Respirable}\mspace{14mu}{fraction}\mspace{14mu}\left( {{RF}(\%)} \right)} = {\left( \frac{FPD}{TD} \right) \times 100\%}} & \left( {{Eq}.\mspace{14mu} 6} \right)\end{matrix}$

A. Materials and Methods

Formulation aerosol performance tests were carried out using a powderdeaggregator modified from that described in U.S. Patent PublicationNos. 2013/0340754 and 2013/0340747 combined with an off-the-shelf RS01dry powder inhaler capsule piercing mechanism (Plastiape, IT) feedingmethod. The powder deaggregator had a 2.72 mm inlet diameter, a 10 mmoscillation chamber length, 5.89 mm oscillation chamber diameter, 4 mmpolypropylene bead (density=0.90 mg/mm³), 2 of 6 bypass channel open,and cross grid. With this capsule piercing mechanism, the deliverysystem had a resistance (RD) of 0.104 (cmH₂O)^(0.5)/L/min. Theexperiments were conducted at an airflow rate that gave a systempressure drop of 2 kPa (about 40 L/min, 4 L inhalation volume duration:5.5 sec) or 4 kPa (about 60 L/min, 4 L inhalation volume duration: 3.9sec).

Formulations: Pure drug formulations (no excipient) of micronizedVarBase, micronized VarHCl.xH₂O, micronized Var(HCl)₂.xH₂O (rehydrated),and micronized VarHCl.xH₂O were prepared as described in Examples 4 and5. Vardenafil blends (5% API and 20% API) with LAC1 were prepared asdescribed in Example 6 using micronized Var(HCl)₂.xH₂O, micronizedVarBase, micronized VarHCl.xH₂O, and micronized VarHCl.3H₂O.

Packaging: The blends were packaged into size 3 HPMC capsules. Nominaldose amounts of 3 mg were prepared for each formulation; 10 mg nominaldoses were also prepared for pure drug VarBase and Var(HCl)₂.xH₂Oformulations.

Methods: Two inertial sampling systems were used to assess aerosolperformance: (1) a Next Generation Impactor® (“NGI”) (Copley Scientific,Shoreview, Minn.), and (2) a Twin Stage Liquid Impinge (“TSLI”) (CopleyScientific, Shoreview, Minn.). Aerosol performance of the VarHCl.xH₂Oformulation was assessed using the TSLI device, while the otherformulations were all assessed using the NGI device. The NGI experimentswere carried out using methods in general agreement with the USP <601>,and the TSLI experiments were carried using methods in general agreementwith the British Pharmacopoeia, 2007, Vol. IV, Appendix XIIF. A291Aerodynamic assessment of fine particles, fine particle dose andparticle size distribution. The NGI experiments were run at a controlledairflow rate that gave a pressure drop of either 2 or 4 kPa across thedevice. Specifically, at Q=61.4 L/min with a delay time of 3.9 sec; andat Q=43.4 L/min with a delay time of 5.5 sec. Before the aerosoltesting, the NGI collection plates were coated with suitable coating.Mass median aerodynamic diameter (MMAD) of aerosol particlesdistribution was determined based on a log-probability distribution (APIparticle size versus API deposition percentage) obtained from the NGIdata. The TSLI experiments were run at Q=60 L/min, 4 sec to achieve ΔP≈4kPa, with a cutoff size of 6.4 μm.

B. Pure Drug Formulations Aerosol Performance

Micronized pure drug formulations (100% API, no excipient) were found togenerally have an emitted dose (ED) fraction in the range of 24-82% andan RF fraction in the range of 21-46%, as shown in Table 5. This wasmainly due to poor powder flow with the delivery system described inSection A. However, the FPF(ED) was generally quite high, except for the10 mg VarBase formulation. The micronized Var(HCl)₂.xH₂O resulted in thehighest FPF(ED), followed by the VarHCl.xH₂O formulation, theVarHCl.3H₂O formulation, and the 3 mg VarBase formulation, each of whichwas well over 50%. Higher dose did not increase the aerosol performancebut did negatively impact FPF(ED) for the VarBase formulation.Rehydration of Var(HCl)₂.xH₂O increased ED and RF markedly but decreasedFPF(ED). The aerosol performance of the pure drug formulations iscomparable to many currently marketed dry powder formulations. However,the way that the capsule piercing mechanism used in these experimentsworks results in a large amount of powder deposition within themechanism itself, which reduces the ED %. Increasing the powder flowproperties of the active agent, such as by adding a suitable dry powderbase (carrier/diluent/excipient) may increase the ED % by facilitatingpowder fluidization during aerosolization. Thus, for use with thedeaggregator-capsule piercing mechanism combination in these studies,improved aerosol performance may be obtained if the vardenafil compoundsare blended with an excipient like lactose.

TABLE 5 Pure Drug Formulation Aerosol Performance Dose MMAD Test API(mg) ED(%) RF(%) FPF(ED)(%) % Recvy (μm) 1 VarBase 3 81.8 45.8 56.0 —1.32 2 VarBase 10 64.2 23.9 37.2 115.2 1.51 3 Var(HCl)₂•xH₂O 3 26.6 23.588.5 — 0.76 4 Var(HCl)₂•xH₂O 10 24.5 21.2 86.5 114.0 0.82 5Var(HCl)₂•xH₂O 3 71.4 45.4 63.6 100.1 1.37 (rehydrated) 6* VarHCl•xH₂O 340.7 28.1 68.9 112.0 — *TSLI data cannot be used to determine MMAD.

C. API-Lactose Formulation Aerosol Performance

In a first experiment, aerosol performance of the 5% Var(HCl)₂.xH₂Oformulation was assessed. In addition to assessing impact of addedlactose as an excipient, the impact of nominal load (or payload) onaerosol performance of this formulation was also assessed. Capsules wereloaded with either 10 mg of formulation or 20 mg of formulation andassessed using the NGI device at 4 kPa airflow rate. The results areshown in Table 6 below (Mean±SD, n=3).

TABLE 6 5% Var(HCl)2•xH2O Formulation at 10 mg or 20 mg Nominal LoadNominal Load ED (%) RF (%) FPF(ED) (%) MMAD (μm) 10 mg 75.1 ± 4.2 51.1 ±4.4 68.0 ± 2.9 0.81 ± 0.01 20 mg 80.5 ± 1.4 53.0 ± 1.4 65.8 ± 0.7 0.84 ±0.02

The ED and RF of the 5% Var(HCl)₂.xH₂O formulation was found to be muchhigher than that of the pure drug Var(HCl)₂.xH₂O formulation, though theFPF(ED) was reduced. The aerosol performance of the formulation wasfound to be independent of the nominal dose at 10 mg or 20 mg as theperformance metrics [ED, RF, FPF(ED)] for each nominal dose were verysimilar. These results suggest that lactose-based formulations mayimprove aerosol performance of dry powder vardenafil formulations, atleast when used with the delivery system described above in Example 7,Section A.

In a second study, the influence of API concentration on the aerosolperformance of lactose-based Var(HCl)₂.xH₂O formulations was evaluated.Capsules were loaded with 20 mg of either the 5% or 20% API formulationand assessed using the NGI device at 4 kPa airflow rate. The results areshown in Table 7 below (Mean±SD, n=3).

TABLE 7 5% + 20% Var(HCl)2•xH2O Formulation at 20 mg Nominal Load APIconc (%) ED (%) RF (%) FPF(ED) (%) MMAD (μm) 5 80.5 ± 1.4 53.0 ± 1.465.8 ± 0.7 0.84 ± 0.02 20 80.1 ± 7.8 60.8 ± 4.8 76.9 ± 1.4 0.92 ± 0.04

The results indicated that the RF can be improved by increasing the APIconcentration from 5% to 20% for this formulation. FPF(ED) also improvedwith increased concentration. These findings suggested that thisdelivery system may be particularly suitable for delivery oflactose-based formulation with high API concentration.

In order to evaluate if the other VarBase and VarHCl.xH₂O formulationshave the same trend, a TSLI device experiment was designed to assesswhether 20% API formulations for VarBase and VarHCl.xH₂O have betteraerosol performance than 5% formulations when the deaggregatordevice-capsule piercing mechanism are used at 4 kPa airflow condition.For each active agent, the 20 mg payload of the 20% formulation includes4 mg of the API, while the 5% formulation includes 1 g of the API. Theresults are shown in Table 8 below. The results for the 5% and 20%VarBase+LAC1 formulations are averaged data (Mean±SD, n=3).

TABLE 8 5% and 20% VarBase and VarHCl•xH₂O Formulation at 60 L/min TestFormulation ED (%) RF (%) FPF(ED)(%) 1 5% VarBase + LAC1 67.2 ± 3.9 26.6± 1.0 39.7 ± 0.9 2 20% VarBase + LAC1 76.4 ± 2.8 42.1 ± 2.7 55.0 ± 1.8 35% VarHCl•xH₂O + 71.7 37.2 51.9 LAC1 4 20% VarHCl•xH₂O + 70.8 48.4 68.4LAC1

The results show that the 20% VarBase and VarHCl.xH₂O also have betteraerosol performance than the corresponding 5% formulations. For theVarBase-LAC1 formulation, the increase of API concentration from 5% to20% resulted in a RF increase from 26.6% to 42.1% and a FPF(ED) increasefrom 39.7% to 55%. For the VarHCl.xH₂O-LAC1 formulation, the same trendheld, with the RF increasing from 37.2% to 48.4% and the FPF(ED)increasing from 51.9% to 68.4%.

Example 8. Very High Dose Formulation Assessment of Aerosol Performance

As the 20% API-lactose blend formulations performed so well, anexperiment was designed to assess the aerosol performance of very highconcentration formulations. High concentration formulations may bedesirable if ED is not reduced as a result. A Dose Unit SamplingApparatus (“DUSA”) (Copley Scientific, Shoreview, Minn.) was used toassess emitted dose of four Var(HCl)₂.xH₂O-LAC1 formulations wereprepared as described in the preceding examples at an API concentrationof 20%, 40%, 60%, and 80%. The DUSA experiments were carried out usingmethods in general agreement with the USP <601>. The same deliverydevice as described above in Example 7, Section A was used. As shown inFIG. 15A, a linear relationship (R²=0.9718) was observed between ED andthe API concentration of the formulation.

To investigate the reason for the observed decrease in emitted dose asseen in FIG. 15A, deposition of the API on the deaggregator and thecapsule piercing mechanism were evaluated separately. These results showthat the amount of the API that was retained in the device was mainly inthe capsule piercing portion of the device, as the amount of depositionin this portion and the formulation concentration were positivelycorrelated (R²=0.9563; y=0.0052x+0.0873; R²=0.9563) as shown in FIG.15B. In contrast, the deposition of API on the deaggregator did notchange as API concentration increased (data not shown). Thus, the 5-20%concentration range may result in about 80% ED for theVar(HCl)₂.xH₂O-LAC1 formulations when used with this delivery system atan airflow of 4 kPa. However, higher concentration formulations may beused with a different device capsule piercing mechanism that dispersesthe drug along the axis of the air flow and not toward the deviceinternal walls like the capsule piercing mechanism used in theseexperiments. In such cases, it can be expected that less loss of drug tothe internal surfaces will be achieved.

Example 9. Influence of Device Pressure Drop on Aerosol Performance

Having aerosol performance of a formulation be independent of airflowconditions is preferable because there is greater reproducibility inadministration where airflow rate may be variable (for example, based onthe user). The NGI device was used to assess the aerosol performance ofthe 20% Var(HCl)₂.xH2O+LAC1 formulation as described above in Example 7,Section A except at an airflow pressure of 4 kPa and 2 kPa(corresponding to about 60 and about 40 L/min airflow rate,respectively). Using the NGI stage cutoffs identified in the USP <601>,the aerosol performance data at the 2 kPa pressure drop was based on NGIcutoff stage 3 and below, and the aerosol performance data at the 4 kPapressure drop was based on NGI cutoff stage 2 and below. The results areshown in Table 9 below (Mean±SD, n=3).

TABLE 9 20% Var(HCl)₂•xH₂O Formulation actuated at 2 kPa vs. 4 kPaAirflow ED (%) RF (%) FPF(ED) (%) MMAD (μm) 2 kPa 75.9 ± 7.5 51.6 ± 2.569.1 ± 2.2 1.15 ± 0.06 4 kPa 80.1 ± 7.8 60.8 ± 4.8 76.9 ± 1.4 0.92 ±0.04

The ED, RF, and FPF(ED) were decreased slightly at 2 kPa as compared to4 kPa. However, the effective aerodynamic cutoff diameter (D_(a50)) foreach impactor stage of the NGI device is different at different flowrates. At 4 kPa, the impactor stage cutoff is 4.41 μm (stage 2 andbelow). In contrast, at 2 kPa the impactor stage cutoff is 3.32 μm(stage 3 and below). As a result, at the faster airflow rate, largersize particles passed the cutoff and contributed to the aerosolperformance. This suggests that the RF and FPF(ED) could be slightlyunderestimated at an airflow rate of 2 kPa. As such, the aerosolperformance at 2 kPa did not appear to cause a substantial change inaerosol performance when compared at 4 kPa.

1. A powder pharmaceutical composition comprising: a) a PDE5 inhibitor or a pharmaceutically acceptable salt or ester thereof, b) a first fraction of fine lactose particles, and c) a second fraction of lactose particles having an average diameter of about 5 μm to about 90 μm; wherein the PDE5 inhibitor or salt or ester thereof is present in an amount of up to about 20% by weight relative to the total weight of the overall pharmaceutical composition; and wherein the first fraction of fine lactose particles is present in an amount of up to about 10% by weight relative to the total weight of the lactose in the composition.
 2. The powder pharmaceutical composition of claim 1, wherein the PDE5 inhibitor is at least one of vardenafil, sildenafil, tadalafil, avanafil, benzamidenafil, lodenafil, mirodenafil, udenafil, or zaprinast, or a pharmaceutically acceptable salt or ester thereof.
 3. The powder pharmaceutical composition of claim 1, wherein the PDE5 inhibitor is vardenafil or a pharmaceutically acceptable salt or ester thereof.
 4. The powder pharmaceutical composition of claim 1, wherein the composition comprises at least about 2% by weight of the PDE5 inhibitor.
 5. The powder pharmaceutical composition of claim 1, wherein the fine lactose particles have an average diameter of less than about 7 μm.
 6. The powder pharmaceutical composition of claim 5, wherein the second fraction of lactose particles has an average diameter about 50 μm to about 90 μm.
 7. The powder pharmaceutical composition of claim 1, wherein the PDE5 inhibitor or salt or ester thereof is present as micronized particles.
 8. The powder pharmaceutical composition of claim 7, wherein the D_(V50) of the micronized particles is up to about 2 μm.
 9. The powder pharmaceutical composition of claim 8, wherein the D_(V50) of the micronized particles is between about 1 μm and about 2 μm.
 10. The powder pharmaceutical composition of claim 1, further comprising calcium stearate, magnesium stearate, leucine, leucine derivatives, lecithin, human serum albumin, polylysine, polyarginine, or other force control agents, or combinations thereof.
 11. The powder pharmaceutical composition of claim 1, wherein the composition is packaged to have a nominal load of about 3 mg to 30 mg.
 12. The powder pharmaceutical composition of claim 1, wherein the composition is packaged to have a nominal dose of at least about 0.25 mg.
 13. The powder pharmaceutical composition of claim 1, wherein the composition is packaged to have a delivered dose of at least about 0.075 mg.
 14. A method of aerosolizing a powder pharmaceutical composition, the method comprising: providing an inhaler comprising a dispersion chamber having an inlet and an outlet, the dispersion chamber containing an actuator that is reciprocatively movable along a longitudinal axis of the dispersion chamber, wherein the dispersion chamber has a geometry configured to produce a flow profile that causes the actuator to repeatedly oscillate within the dispersion chamber; and inducing air flow through the outlet channel to cause air and the powder pharmaceutical composition to enter into the dispersion chamber from the inlet, and to cause the actuator to oscillate within the dispersion chamber to assist in dispersing the powder pharmaceutical composition from the outlet for delivery to a subject through the outlet, wherein the powder pharmaceutical composition is a composition according to claim 1; and wherein the PDE5 inhibitor or pharmaceutically acceptable salt or ester thereof has a mass median aerodynamic diameter of up to about 5 μm and a fine particle fraction of at least about 40% upon aerosolization.
 15. The method of claim 14, wherein the powder pharmaceutical composition has a mass median aerodynamic diameter of up to about 5 μm upon aerosolization.
 16. The method of claim 15, wherein the powder pharmaceutical composition has a mass median aerodynamic diameter of between about 0.5 μm and about 5 μm upon aerosolization.
 17. The method of claim 14, wherein the powder pharmaceutical composition has a fine particle fraction of at least about 20% upon aerosolization.
 18. The method of claim 14, wherein the powder pharmaceutical composition is stored within a storage compartment, and wherein the powder pharmaceutical composition is transferred from the storage compartment, through the inlet and into the dispersion chamber.
 19. The method of claim 14, wherein the inlet is in fluid communication with an initial chamber, and wherein the powder pharmaceutical composition is received into the initial chamber prior to passing through the inlet and into the dispersion chamber.
 20. A method of treating a disease or condition in a subject in need thereof, the method comprising administering to the subject via a pulmonary route an effective amount of powder pharmaceutical composition according to claim
 1. 21. The method of claim 20, wherein the disease or condition is a lung disease or condition or a heart disease or condition or a combination thereof.
 22. The method of claim 20, wherein disease is pulmonary hypertension, cystic fibrosis, or congestive heart failure.
 23. The method of claim 22, wherein the pulmonary hypertension includes pulmonary arterial hypertension, primary pulmonary hypertension, secondary pulmonary hypertension, familial pulmonary hypertension, sporadic pulmonary hypertension, precapillary pulmonary hypertension, pulmonary artery hypertension, idiopathic pulmonary hypertension, thrombotic pulmonary arteriopathy, plexogenic pulmonary arteriopathy and pulmonary hypertension associated with or related to, left ventricular dysfunction, mitral valvular disease, constrictive pericarditis, aortic stenosis, cardiomyopathy, mediastinal fibrosis, anomalous pulmonary venous drainage, pulmonary venoocclusive disease, collagen vascular disease, congenital heart disease, congenital heart disease, pulmonary venus hypertension, chronic obstructive pulmonary disease, interstitial lung disease, lung fibrosis, sleep-disordered breathing, alveolarhyperventilation disorder, chronic exposure to high altitude, neonatal lung disease, alveolar-capillary dysplasia, sickle cell disease, coagulation disorders, chronic thromboemboli, connective tissue disease, lupus, schistosomiasis, sarcoidosis or pulmonary capillary hemangiomatosis.
 24. The method of claim 20, wherein the powder pharmaceutical composition is administered using a dry powder inhaler or a metered dose inhaler. 